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Northern Indiana Public Service Company, LLC v. Department Of State Revenue

2026-08-31

Summary

Holding. The motion to exclude Williams' testimony is granted in part and denied in part. Williams is qualified to testify regarding the general nature of electricity and aspects of the electric industry, but not to interpret specific regulatory filings; portions of his reports containing legal conclusions are stricken.

This case involves a motion to exclude expert testimony from John A. Williams, an engineer with advanced degrees in chemical and fuels engineering, who was retained by the Indiana Department of State Revenue in a tax dispute. NIPSCO sought to exclude Williams' expert reports and testimony on grounds that he lacked qualifications, used unreliable methodology, and offered inadmissible legal conclusions. The central issue was whether electricity qualifies for Indiana's public transportation exemption on sales and use taxes.

The court found that Williams was qualified to testify about the general physical nature of electricity and the electric utility industry broadly, including how grids operate, NIPSCO's business model, and the regulatory framework. However, the court determined that Williams was not qualified to interpret specific regulatory filings and accounting conventions, such as FERC forms and IURC tariff schedules, because those require specialized regulatory accounting expertise that he did not possess. Additionally, the court identified several statements in Williams' reports that constituted inadmissible legal conclusions, including interpretations of Indiana statutes and applications of law to facts.

Summary generated by law.co from the public-domain opinion. The opinion text itself is public domain.

Key issues

  • Expert qualification requirements under Indiana Evidence Rule 702(a) for specialized fields
  • Whether general engineering expertise extends to interpretation of regulatory accounting documents
  • Distinction between admissible ultimate-issue opinions and inadmissible legal conclusions under Rule 704(b)
  • Reliability of scientific principles underlying expert testimony under Rule 702(b)

Procedural posture

This is a motion to exclude expert testimony filed in an Indiana Tax Court proceeding in which NIPSCO seeks a refund of sales and use taxes paid on equipment, claiming eligibility for a public transportation exemption.

Authorities cited

Opinion

majority opinion

ATTORNEYS FOR PETITIONER: ATTORNEYS FOR RESPONDENT:

RANDAL J. KALTENMARK THEODORE E. ROKITA

STEVEN A. BALDWIN ATTORNEY GENERAL OF INDIANA

DARRICK J. HOOKER JEFFERSON S. GARN

BARNES & THORNBURG LLP MICHELLE R. WYATT

Indianapolis, IN SHELBY M. STOUDER

DEPUTY ATTORNEYS GENERAL

Indianapolis, IN

IN THE

INDIANA TAX COURT

NORTHERN INDIANA PUBLIC SERVICE ) FILED COMPANY, LLC ) Aug 31 2026, 2:35 pm

) CLERK

Petitioner, ) Indiana Supreme Court

Court of Appeals

and Tax Court

)

v. ) Case No. 24T-TA-00017

)

INDIANA DEPARMENT OF )

STATE REVENUE, )

)

Respondent. )

ORDER ON NIPSCO’S MOTION TO EXCLUDE TESTIMONY OF

PUTATIVE EXPERT JOHN A. WILLIAMS

FOR PUBLICATION

August 31, 2026

MCADAM, J.

This matter concerns Northern Indiana Public Service Company, LLC’s Motion to

Exclude the two expert witness reports and related testimony of the Indiana Department

of Revenue’s expert, John A. Williams—a professional engineer with academic and

professional experience reaching topics in electrical engineering. Northern Indiana

Public Service Company, LLC (“NIPSCO”) contends that Williams lacks qualifying

experience to offer opinions on the topics covered in his reports, uses unscientific

reasoning or methodology, and offers inadmissible legal conclusions. The Indiana

Department of Revenue asserts that Williams has relevant expertise in engineering and

electrical transmission systems, provides reliable and scientifically valid testimony, and

testifies on ultimate issues. The Court finds that Williams is qualified to offer opinions

concerning (1) the general nature of electricity and (2) the electric industry at large and

NIPSCO’s company overview, business model, and role within the industry. As to the

first, the Court further finds that his testimony rests on reliable scientific principles. The

Court finds, however, that the Department has not shown Williams to be qualified to

interpret or rely upon NIPSCO’s regulatory filings. And, in the testimony that remains,

the Court identifies inadmissible legal conclusions.

FACTS AND PROCEDURAL HISTORY

NIPSCO seeks a refund of the Indiana sales and use tax that it paid on

purchases of tangible personal property that it used or consumed to transport electricity

owned by third parties during 2015, 2016, and 2017. The Department denied NIPSCO’s

refund request, but NIPSCO contends that it is entitled to the public transportation

exemption provided in Indiana Code § 6-2.5-5-27. (Jt. Stip. at 2 ¶¶ 3–7.)

Following discovery, the Parties filed cross-motions for summary judgment,

which are currently pending before the Court. NIPSCO seeks partial summary judgment

on the question of whether electricity is eligible for the public transportation exemption

as property or as a physical object. (See Pet’r’s Mot. Partial Summ. J. at 3.) The

Department has filed its own motion for summary judgment and retained John A.

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Williams as an expert. (See Resp’t’s Mot. Summ. J. at 1–2.) Williams is the subject of

the motion before the Court.

Williams produced two reports for the Department’s summary judgment motion.

In the first report, Williams covered topics on the nature of electricity, including the

fundamental physics of electricity, electricity generation methods, transmission and

propagation characteristics, and electrical grid and transmission line physics. (Pet’r’s Br.

Supp. Mot. Exclude Test. Ex. A, at 3.)1 He also testified about NIPSCO’s business

model and services, the energy regulatory framework, various regulatory reports filed by

NIPSCO, distinctions between electricity and transportation, and industry terminology

and standards. (Pet’r’s Br. Ex. A, at 3.) In his second report, Williams rebutted the

claims and assertions made in the report of NIPSCO’s expert, John Loud. (Pet’r’s Br.

Ex. B, at 2.) Williams clarified the distinctions between electrons as a medium and

energy as a service, as well as energy propagation and electron drift. (Pet’r’s Br. Ex. B,

at 3.) Williams also covered topics such as the real-time balance requirement, the flaws

in Loud’s definitions and analogies, and industry terminology. (Pet’r’s Br. Ex. B, at 3.)2

Williams has an academic background in engineering, having obtained master’s

and doctorate degrees in chemical and fuels engineering from the University of Utah.

(Resp’t’s Br. Ex. 1, at 3.) His master’s thesis and Ph.D. dissertation included topics in

electrical engineering. (See Pet’r’s Br. Ex. C, at 11:18–12:3, 15:13–25.) He has taught

courses that include discussions of electricity and electron behavior and has served as

1

For ease of the reader, Petitioner’s Brief in Support of its Motion to Exclude Testimony of Putative Expert John A. Williams shall be hereinafter referred to as “Pet’r’s Br.” in citations. The same shall be true for Respondent’s Response to Petitioner’s Motion to Exclude Testimony of Putative Expert John A. Williams, which shall be hereinafter referred to as “Resp’t’s Br.” in citations.

2

For ease of the reader, Pet’r’s Br. Ex. A shall be hereinafter referred to as “Opening Report” in citations, and Pet’r’s Br. Ex. B shall be hereinafter referred to as “Rebuttal Report.”

3

an Adjunct Professor at the University of Utah in the Department of Chemical

Engineering. (Resp’t’s Br. Ex. 1, at 1; Resp’t’s Br. Ex. 2, ¶ 7.) In addition to his academic

experience, Williams has obtained his Professional Engineering Licensure in twentyseven states, including Indiana, served for thirty-one years as the general manager for a

professional engineering firm that has “engineered, analyzed, and constructed industrial

facilities containing electrical power transmission and distribution systems,” and worked

as a consultant to analyze electrical transmission and distribution for large electric utility

companies. (Resp’t’s Br. Ex. 2, ¶¶ 3, 5–6; see Resp’t’s Br. Ex. 1, at 2.)

NIPSCO has moved to exclude Williams’ two reports and testimony related to

them.

DISCUSSION

NIPSCO moves to exclude Williams’s reports and any related testimony on three

grounds under Rules 702 and 704 of the Indiana Rules of Evidence. Namely, NIPSCO

argues that (1) Williams lacks the expertise to offer opinions on the electric industry, its

regulation, and NIPSCO’s business; (2) his opinions do not rest on scientifically valid

reasoning or methodology; and (3) his reports offer only inadmissible legal conclusions.

(Pet’r’s Br. at 2.)

The Court resolves those grounds as follows. Applying Indiana Evidence Rule

702(a) to Williams’ proffered opinions, the Court finds that he is qualified to testify about

the general nature of electricity. As to that category of testimony, the Court finds that the

Department has shown it rests upon reliable scientific principles—the principles are of a

foundational nature and generally accepted—and so satisfies Indiana Evidence Rule

702(b). The Court also finds that Williams is qualified to testify about several topics,

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such as how the grid and utilities are designed, operated, and coordinated, and

generally what NIPSCO’s business is and how it fits in the industry, but that he is not

qualified to speak to the interpretation of NIPSCO’s regulatory filings or apply that

interpretation to questions in this case. Finally, addressing NIPSCO’s objection under

Indiana Evidence Rule 704(b), the Court identifies impermissible legal conclusions

among the opinions that survive the qualification analysis.

I. Williams’ Qualifications and Scientific Reliability under Rule 702

“Evidentiary rulings, including a decision to exclude expert testimony, lie solely

within the trial court’s discretion.” Lytle v. Ford Motor Co., 814 N.E.2d 301, 308 (Ind. Ct.

App. 2004). Affidavits presented on summary judgment must “set forth such facts as

would be admissible in evidence.” Ind. Tr. R. 56(E) (eff. Jan 1, 2008). Therefore, such

affidavits must comply with the requirements for expert testimony in Indiana Evidence

Rule 702, which provides:

(a) A witness who is qualified as an expert by knowledge, skill, experience,

training, or education may testify in the form of an opinion or otherwise if the

expert’s scientific, technical, or other specialized knowledge will help the

trier of fact to understand the evidence or to determine a fact in issue.

(b) Expert scientific testimony is admissible only if the court is satisfied that

the expert testimony rests upon reliable scientific principles.

Ind. R. Evid. 702 (eff. Jan. 1, 2014).

The admission of expert testimony is committed to the Court’s discretion in its

role as gatekeeper. See McDaniel v. Robertson, 83 N.E.3d 765, 773 (Ind. Ct. App.

2017). The proponent of the testimony—here, the Department—bears the burden of

establishing that the witness is qualified. Witte v. Mundy ex rel. Mundy, 820 N.E.2d 128,

135 (Ind. 2005) (“The [proponents] had the burden of establishing the ability of

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their witness to give the proffered testimony.”).

To satisfy Rule 702(a) of the Indiana Rules of Evidence, the party seeking to

introduce the testimony must meet two requirements. First, the subject matter must be

“distinctly related to some scientific field, business, or profession beyond the knowledge

of the average lay person”; and second, the witness must be “shown to have sufficient

skill, knowledge or experience in that area so that the opinion will aid the trier of fact.”

Bacher v. State, 686 N.E.2d 791, 800 (Ind. 1997). Qualification may rest on one or more

of the distinctive bases named by the Rule—knowledge, skill, experience, training, or

education. See Fueger v. Case Corp., 886 N.E.2d 102, 104 (Ind. Ct. App.) (citing Lytle,

814 N.E.2d at 308), aff’d on reh’g sub nom. Fueger v. CNH Am. LLC, 893 N.E.2d 330

(Ind. Ct. App. 2008).

Critically, qualification is subject-matter specific. “[A]n expert must have sufficient

skill in the particular area of expert testimony before an opinion may be offered in that

area.” Id. “An expert in one field of expertise cannot offer opinions in other fields absent

a requisite showing of competency in that other area,” id., such that “before an expert

may testify in an area, the proponent of the expert must show that the expert is

competent in that area,” Armstrong v. Cerestar USA, Inc., 775 N.E.2d 360, 366 (Ind. Ct.

App. 2002) (citing Hannan v. Pest Control Servs., Inc., 734 N.E.2d 674, 679 (Ind. Ct.

App. 2000), trans. denied). Said differently, a witness’s competence in a general field

does not automatically extend to every specialized subject that field may touch.

That said, once threshold competence in the relevant field is established, finer

gaps in the witness’s command of a subfield ordinarily go to weight rather than

admissibility. “A witness’ competency is determined by his knowledge of the subject

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matter generally, and his knowledge of the specific subject of inquiry goes to the weight

to be accorded his opinion, not its admissibility.” McIntosh v. Cummins, 759 N.E.2d

1180, 1185 (Ind. Ct. App. 2001) (citing Snyder v. Cobb, 638 N.E.2d 442, 446 (Ind. Ct.

App. 1994), trans. denied), trans. denied. These two concepts work in tandem. The

proponent must first show competence in a particular field before the witness may opine

in it. After that threshold has been crossed, the absence of subfield expertise is a matter

of weight. See id. Where, however, the proponent has not carried the threshold showing

of competence in the relevant field, the McIntosh weight principle does not apply, and

exclusion is the appropriate course. See, e.g., Goodwin v. Toney, 203 N.E.3d 481, 486

(Ind. Ct. App. 2022), trans. denied.

Where an expert’s opinion rests on the application of scientific principles, Rule

702 imposes a second and independent requirement: the proponent must additionally

establish—and the court must be satisfied—that those scientific principles are reliable.

Ind. R. Evid. 702(b); Fueger, 886 N.E.2d at 105. “When faced with a proffer of expert

scientific testimony, the court must make a preliminary assessment of whether the

reasoning or methodology underlying the testimony is scientifically valid and whether

that reasoning or methodology properly can be applied to the facts in

issue.” Hannan, 734 N.E.2d at 679. On summary judgment, however, the “reliability of

the scientific principles need not be established, but the trial court must be provided with

enough information to proceed with a reasonable amount of confidence that the

principles used to form the opinion are reliable.” Doe v. Shults-Lewis Child & Fam.

Servs., Inc., 718 N.E.2d 738, 750–51 (Ind. 1999). The burden of making that showing

falls on the proponent. Spaulding v. Harris, 914 N.E.2d 820, 829 (Ind. Ct. App. 2009)

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(proponent bears the burden of establishing “the foundation and reliability of the

scientific principles and tests upon which the expert’s testimony is based”).

The reliability inquiry is flexible rather than formulaic: “there is no specific ‘test’ or

set of ‘prongs’ which must be considered in order to satisfy Indiana Evidence Rule

702(b).” McGrew v. State, 682 N.E.2d 1289, 1292 (Ind. 1997). Such factors may

include: “whether the technique has been or can be empirically tested; [] whether the

technique has been subjected to peer review and publication; . . . [or] general

acceptance within the relevant scientific community.” Id. at 1292 n.5 (citing Daubert v.

Merrell Dow Pharmaceuticals, 509 U.S. 579, 593–595 (1993)).

A. The Reports and Subjects on which Williams Opines

Williams’ two reports address several analytically distinct subjects. For purposes

of the qualifications and reliability inquiries, the Court adopts the groupings used by the

parties and organize them into two buckets as follows: (1) the general, foundational,

nature of electricity; and, (2) the design, operation, coordination, and regulation of the

electric-utility industry, including NIPSCO’s operations within the industry. These

categories are interspersed throughout the report—accordingly, the Court will not go

line-by-line to identify where category is discussed but rather speak about them

generally.

1. Category 1 – The general nature of electricity

For good portions of both reports, Williams describes what electricity is and how

it behaves as a matter of physical science: that electrical energy propagates as an

electromagnetic field; that electrons drift or oscillate in place rather than travel end-toend from generator to customer; and that, as a matter of physics, generation and load

8

must remain in instantaneous balance.

2. Category 2 – The electric-utility industry

NIPSCO believes that Williams cannot speak about the industry that delivers

electricity, nor NIPSCO’s participation in it, because he does not know how it is built,

run, or regulated. NIPSCO assigns several different topics of Williams’ testimony to the

second category, gathering various subjects on which NIPSCO contends Williams is

unqualified to opine about: (1) “the electric industry”; (2) “NIPSCO’s operations”; (3) “the

functioning of regional grid networks”; (4) “the design, operation, or coordination of

electric transmission systems”; or, (5) “the complex regulatory frameworks governing

electric utilities.” (Pet’r’s Br. at 9, 11.) The defining feature of all five for purposes of Rule

702(a) is that each demands specialized knowledge of how the electric-utility industry

and its component parts are operated, coordinated, and regulated—the applied

expertise of the electric-power industry—as opposed to the physical science of

electricity that defines the first category. Whether the subject is a transmission system’s

design, a regional grid’s coordination, NIPSCO’s operations or place within the

industry—such as its company overview, being set up as a vertically integrated public

utility offering bundled service, or whether a provider is subject to FERC jurisdiction3—

the competence required is that of an electric-utility professional, not a scientist.

B. Analysis of the Reports and Williams’ Opinions

The parties disagree about the extent of Williams’ qualifications to testify about

each category. As to the first category—testimony about the general nature of

electricity—the parties generally agree that Williams is qualified to testify on this subject

3

“FERC” stands for the Federal Energy Regulatory Commission.

9

matter.4 The parties differ sharply regarding the second category—testimony about the

electric-utility industry in general. NIPSCO contends that Williams is not qualified to

testify to anything falling within the ambit of this topic because, according to NIPSCO,

he has no expertise or experience in the regulation of electricity transmission or the

electric industry. The Department, pointing to Williams’ education and experience,

argues that he is competent in each category.

The Court finds Williams’ education and experience to be sufficient to permit his

testimony concerning the first category. Furthermore, the Court finds the testimony in

this first category to rest on reliable scientific principles. For the second category,

however, the Court finds that Williams is qualified in part. Based on his experience, he

can speak generally about the electric industry, NIPSCO’s company overview and

business model as a bundled service provider, the functioning of regional grid networks,

the design, operation, or coordination of electric transmission systems, and the

electrical utility regulatory framework. But, the Court finds that the Department has not

shown that Williams is qualified to opine on the meaning of specific regulatory

instruments and reports, independently or as they pertain to NIPSCO.

4

NIPSCO appears in its initial brief to challenge that Williams has no expertise in electricity transmission. (Pet’r’s Br. at 9 (“Having no expertise or experience in electricity transmission, . . . Williams is not an expert capable of testifying on these topics and his opinions should be excluded.”).) However, NIPSCO clarified at oral argument that, given his background, Williams should be allowed to opine on whether “electricity is a physical object, [] it [can] be felt, tasted, . . . perceived by the senses,” as well as on “how electricity works.” (Aug. 13, 2026 Oral Tr. at 14.) It also indicated that it did not “take issue with [] Williams’ ability to opine on fundamental concepts of electricity.” (Aug. 13, 2026 Oral Tr. at 52.)

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1. Category 1 – Williams is qualified to describe the general nature of

electricity

The relevant field is the general physical science of electricity—what electricity is

and how, as a matter of physics, it is generated, propagates, and behaves. The first

702(a) element is plainly met: the fundamental physics of electromagnetic energy lies

beyond the knowledge of the average layperson.

The second qualification element is also met. Williams holds advanced degrees

in chemical and fuels engineering, with his master’s and Ph.D. degrees involving

electric engineering coursework and at least his master’s thesis involving a highpressure reaction system that had electrical components, controls, and monitoring.

(Resp’t’s Br. Ex. 1, at 3; Pet’r’s Br. Ex. C, at 11–12.) Williams serves as an Adjunct

Professor at the University of Utah’s Department of Electrical & Computer Engineering,

where he has taught courses that discuss electricity and electron behavior. (Resp’t’s Br.

Ex. 1, at 1; Resp’t’s Br. Ex. 2, ¶ 7.) He has also presented on the transmission of

energy. (Pet’r’s Br. Ex. C, at 32:12–14.) As Williams explains, chemical engineering is

“very focused on energy, energy conversion, and energy systems,” and chemical

engineers are trained “to understand and be technically proficient in . . . electrical

physics [and] electrical engineering.” (Pet’r’s Br. Ex. C, at 20:17–18, 20:24–21:1.)

In addition to his academic experience, Williams has obtained his Professional

Engineering License in twenty-seven states, including Indiana. (See Resp’t’s Br. Ex. 1,

at 2.) “[A]s a licensed professional engineer, [Williams has] demonstrated a competency

in electrical engineering.” (Pet’r’s Br. Ex. C, at 16:21–24; see also Pet’r’s Br. Ex. C, at

26:24–27:16.) He has served for thirty-one years as the general manager for a

professional engineering firm that has “engineered, analyzed, and constructed industrial

11

facilities containing electrical power transmission and distribution systems.” (Resp’t’s Br.

Ex. 2, ¶ 3.) In a consultant role, he has analyzed electrical transmission and distribution

for large electric utility companies. (Resp’t’s Br. Ex. 2, ¶ 6.) He also testified to having

completed several investigations concerning electrical failure analysis. (Pet’r’s Br. Ex. C,

at 16:14–15.) A witness with this training and experience possesses “sufficient skill,

knowledge or experience” to explain the general physical character of electricity so as to

aid the trier of fact. Bacher, 686 N.E.2d at 800.

NIPSCO’s objection that Williams is a chemical and fuels engineer rather than an

electrical engineer does not defeat qualification as to this category. NIPSCO has not

offered any evidence that the general physics of electricity is the exclusive province of

electrical engineering. There is adequate support for the conclusion that knowledge of

electricity falls within the competence of a broadly trained engineer. Williams’

description of the licensing examination for engineers is similar to the bar examination

for lawyers; in both professions, the licensed professional is expected to have and is

tested on a range of subspecialties within the broader field. (See Pet’r’s Br. Ex. C, at

26:25 –27:7.) The distinction NIPSCO attempts to draw is one that our courts assign to

weight rather than admissibility. See McIntosh, 759 N.E.2d at 1185. The Court therefore

finds that the Department has carried its burden of qualifying Williams to offer testimony

describing the general nature of electricity.

Because the Category 1 testimony rests on the application of scientific

principles—the physics of electricity—it carries the additional reliability requirement of

Rule 702(b). The Court has a reasonable amount of confidence that the Category 1

principles are reliable. The propositions Williams advances at this level of generality—

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that electricity is electromagnetic energy; that electrons drift or oscillate in place rather

than travel end-to-end from generator to customer; and that generation and load must

remain in instantaneous balance—appear foundational and generally accepted. See

PSI Energy, Inc. v. Home Ins. Co., 801 N.E.2d 705, 739 (Ind. Ct. App. 2004)

(“Widespread acceptance can be an important factor in ruling whether particular

evidence is admissible under [Evidence Rule] 702.”), trans. denied. The reliability of

these foundational principles—as distinct from their application to NIPSCO—is not in

genuine dispute,5 and Williams grounds them in a scientific treatise, Kuphaldt’s Lessons

in Electric Circuits, which this Court notes that NIPSCO’s own expert relies upon in part

in his report attached to the motion for summary judgment, (see Pet’r’s Mot. Partial

Summ. J. & Designation of Evid. Ex. C, at 9.) The Department has therefore carried its

burden on reliability as to the Category 1 principles.

2. Category 2 – Williams is qualified to opine on the electric industry

generally, but is not qualified to interpret specific regulatory filings

The subjects in this category lie beyond the knowledge of the average layperson,

so the first Rule 702(a) element is met. The contested question is the second—whether

Williams has sufficient skill, knowledge, or experience in this field to aid the trier of

fact—and the burden of showing it is met is the Department’s. The threshold that

showing must clear is not demanding. Qualification may rest on any of the disjunctive

bases Rule 702(a) names—knowledge, skill, experience, training, or education. A

witness’ competency is determined by his knowledge of the subject matter generally,

and his knowledge of the specific subject of inquiry goes to the weight to be accorded

5

Importantly, when asked at oral argument about whether it was challenging “his testimony regarding the principles of electricity or the nature of electricity . . . under 702(b),” NIPSCO affirmed, indicating “not in [a] vacuum.” (Aug. 13, 2026 Oral Tr. at 6.)

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his opinion, not its admissibility. McIntosh, 759 N.E.2d at 1185.

Measured against that threshold, the Department’s showing of Williams’

experience suffices for the bulk of his Category 2 testimony. Williams’ engineering

career spans more than thirty-five years. As described previously, he has served for

thirty-one years as the general manager for a professional engineering firm that has

“engineered, analyzed, and constructed industrial facilities containing electrical power

transmission and distribution systems.” (Resp’t’s Br. Ex. 2, ¶ 3.) He has also served as

a consultant for or analyzed the operations of several electric utility companies,

including Florida Power and Light, Luminant, Pacific Gas and Electric, ComEd, and

Exelon. (Resp’t’s Br. Ex. 2, ¶¶ 5, 6.) According to his testimony, many of the analyses

he has done have been “work for or about utilities.” (Pet’r’s Br. Ex. C, at 23:9–10.) He

has done work involving MISO.6 (Pet’r’s Br. Ex. C, at 24:24–25.) He is a licensed

Professional Engineer and a Fellow of the American Institute of Chemical Engineers,

and he has presented on how regulation bears on the energy industry. (Resp’t’s Br. Ex.

1, at 1, 3–4.) That experience reflects sufficient general knowledge of how electric

transmission and distribution systems, the regional grids they form, and the utilities that

operate them are designed, run, and coordinated to permit Williams to opine on those

subjects and to aid the trier of fact. He is therefore qualified to testify concerning the

design, operation, and coordination of electric transmission systems, the functioning of

regional grid networks, the electrical utility regulatory framework, NIPSCO’s company

overview, service territory, and general operations, and the electric industry generally.

The deficiencies NIPSCO identifies do not defeat that qualification; they bear on the

6

“MISO” stands for the Midcontinent Independent System Operator.

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weight the Court may ultimately give the opinions. See McIntosh, 759 N.E.2d at 1185.

Nevertheless, one subject within this large category stands on a different footing.

Throughout his reports, Williams interprets the meaning of specific regulatory

instruments, including NIPSCO’s FERC Form 1 Annual Report of Major Electric Utilities,

Licensees and Others and Supplemental Form 3-Q Quarterly Financial Report, FERC

Form 1 Electric Energy Account and Monthly Transmission System Peak Load data,

FERC Electric Quarterly Report transaction summaries, FERC Form 566, the FERC

Uniform System of Accounts, NERC reliability standards, the EIA-861 and EIA-923

forms, and IURC tariff schedules.7 To the extent that Williams offers not a description of

how the utility industry writ large operates but an expert interpretation of NIPSCO’s

regulatory filings and then relies upon that interpretation to offer conclusions about

NIPSCO’s operations, etc., the Department has not shown that he is competent to do

so.

Interpreting those instruments is not an exercise in engineering but in regulatory

accounting: it requires specialized knowledge of the conventions by which utilities

classify and report their activities under the regulatory scheme. The Department has

identified no degree, training, or experience of Williams in the discipline of regulatory

accounting, and the general industry and energy-engineering experience that qualifies

him does not supply it. In the deposition portion provided to the Court, Williams was

able to describe FERC, MISO, the IURC, and NERC in general terms. (See Pet’r’s Br.

Ex. C, at 24:10–26:19.) Beyond that, however, the submissions are silent where it

matters. The Department does not provide evidence describing what Williams did in the

7

“NERC” stands for the North American Electric Reliability Corporation. “IURC” stands for the Indiana Utility Regulatory Commission.

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“analyses” he testified had “involved” MISO, (Pet’r’s Br. Ex. C, at 24:24–25,) or in the

utility consulting his affidavit recites, (see Resp’t’s Br. Ex. 2, ¶¶ 5, 6.) Though Williams

has three professional presentations titled “How Do Regulations Affect the Energy

Industry” (for years 2016, 2017, and 2019), the Court is not satisfied that these

presentations involve the knowledge that is required. The Department has not described

their content at all, nor indicated that these presentations involve the regulatoryaccounting conventions that govern the specific filings at issue. By themselves, the titles

suggest that these presentations were aimed at a generalized treatment of how

regulation bears on the energy industry rather than any command of electric-utility

regulatory practice or how to interpret particular compliance filings.

Here the shortfall is not a matter of weight but of threshold competence. In this

respect, Williams’ situation resembles two cases in which Indiana courts held that

general skill in a field did not qualify a witness to opine on a specialized subject within it.

In Cansler v. Mills, 765 N.E.2d 698 (Ind. Ct. App. 2002), trans. denied, the Court

of Appeals addressed whether an auto mechanic was qualified to give expert testimony

that a Corvette’s air bag should have deployed. The Court upheld the trial court’s finding

that the mechanic was unqualified under Rule 702(a) to opine on air bag deployment:

although he had “examined numerous wrecked automobiles with deployed air bags”

and his automotive-repair experience gave him “some knowledge” of the subject, he

had never consulted on a defective air bag, never trained on air bags, and never

designed, tested, or certified air bag systems, and thus lacked “enough experience with

the fundamentals of air bag deployment to qualify him as an expert in the area.” Id. at

702, 703.

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Hegerfeld v. Hegerfeld, 555 N.E.2d 853 (Ind. Ct. App. 1990), is to the same

effect. There, the Court of Appeals reversed a marital-property division after the trial

court permitted a certified public accountant to testify as an expert to the present value

of pension benefits. Accounting skill alone was not enough; the proponent of the expert

needed to demonstrate that he “possessed, in addition to his skill as an accountant,

knowledge of the process of ascertaining the present value of pension benefits,” and

had failed to do so.8 Id. at 856. Command of the broad field did not carry over since the

witness must have demonstrated, but did not demonstrate, “that he knows . . . what the

data represent[ed] and . . . why or how that data applie[d]” to the case. Id. The

deficiency was fundamental.

So too here. The Department has shown that Williams is an experienced energy

engineer and industry consultant, and that experience qualifies him to speak generally

to how utilities and the grid operate. But interpreting NIPSCO’s regulatory documents is

the analogue of opining on air-bag deployment or valuing a pension: a specialized

subject that demands competence the general credential or experience does not

supply. The Department has identified nothing in Williams’ background that supplies

that competence, and the burden to do so was its own. See Armstrong, 775 N.E.2d at

366 (“[B]efore an expert may testify in an area, the proponent of the expert must show

that the expert is competent in that area.”)

The Court thus finds that, although Williams is qualified to opine on the design,

operation, and coordination of electric transmission systems, the functioning of regional

grid networks, NIPSCO’s business model and utility operations, and the electric industry

8

While Hegerfeld was decided prior to Rule 702’s adoption, its analysis of expert qualifications is similar to that required under the rule. See generally 555 N.E.2d at 855.

17

generally, the Department has not carried its burden of qualifying Williams to interpret or

apply NIPSCO’s regulatory filings or the regulatory-accounting conventions that govern

them.9

II. Inadmissibility of Legal Conclusions under Rule 704

NIPSCO also contends that Williams’ reports and related testimony should be

excluded under Rule 704 of the Indiana Rules of Evidence, as his “reports offer only

inadmissible legal conclusions dressed up as expert opinions.” (Pet’r’s Br. at 2).

NIPSCO argues that Williams offers legal conclusions that are based on application of

relevant law to the facts of the case and impermissibly address the public transportation

exemption and NIPSCO’s compliance with its statutory and regulatory requirements. It

specifically calls out “Williams’ conclusion that NIPSCO provides ‘energy’ as a retail

service and does not transport electricity as contemplated by the exemption” as

“foundational to both of his reports.” (Pet’r’s Br. at 6.) The Department argues that

Williams “offers scientific background, context, and analysis of the ultimate issues in this

matter” and contends that the Court is free to disregard any legal conclusions should

they exist. (Resp’t’s Br. at 2).

Indiana Evidence Rule 704 “generally allows opinions to embrace ultimate issues

to be decided by the trier of fact.” Tell City Boatworks, Inc. v. Ind. Dept. of State Revenue,

123 N.E.3d 728, 731 (Ind. Tax Ct. 2019). However, a witness may not testify to legal

conclusions. Ind. Evid. R. 704(b). A legal conclusion occurs when an “expert states his

9

The Court reaches Rule 702(b) only as to Category 1. Rule 702(b) is triggered only by testimony resting on scientific principles. Williams’ Category 2 opinions are experience-based, or specialized-knowledge testimony, not scientific-principles testimony. See Malinski v. State, 794 N.E.2d 1071, 1085 (Ind. 2003) (quoting Jervis v. State, 679 N.E.2d 875, 881 (Ind. 1997)) (testimony resting on “specialized knowledge” rather than “scientific principles” is not subject to Rule 702(b)).

18

opinion as to how the case should be decided.” City of Columbia City v. Ind. Util. Regul.

Comm’n, 618 N.E.2d 21, 28 (Ind. Ct. App. 1993), reh’g denied. Testimony that draws

“conclusions based on application of the relevant law to the facts of the case” are legal

conclusions. Kelly v. Levandoski, 825 N.E.2d 850, 864 (Ind. Ct. App. 2005); see also,

e.g., Schumm v. State, 868 N.E.2d 1202, 1204 (Ind. Ct. App. 2007) (indicating that

evidence relating to whether the defendant complied with regulations requires the witness

to draw a legal conclusion). Interpretations of the law also constitute inadmissible legal

conclusions. See Indianapolis Podiatry, P.C. v. Efroymson, 720 N.E.2d 376, 383 (Ind. Ct.

App. 1999), trans. denied; see also Cincinnati SMSA Ltd. P’ship v. Ind. Dept. of State

Revenue, No. 49T10-0409-TA-45, 2009 WL 2783705, at *5 (Ind. Tax Ct. Aug. 21, 2009)

(indicating testimony based upon the expert’s interpretation of the Mobile

Telecommunications Sourcing Act was an inadmissible legal conclusion); Hacker v.

Holland, 570 N.E.2d 951, 953 (Ind. Ct. App. 1991) (citing Walker v. Lawson, 526 N.E.2d

968, 970) (Ind. 1988)). “The purpose of the rule is that legal conclusions from a witness

are not helpful to the trier of fact; the judge, not an expert witness, instructs on the law.”

Kelly, 825 N.E.2d at 864 (quoting Vaughn v. Daniels Co. (West Virginia), 777 N.E.2d

1110, 1122–123 (Ind. Ct. App. 2002)).

In contrast, “Indiana Evidence Rule 704 permits opinions to embrace ultimate

issues to be decided by the trier of fact.” Vaughn v. Daniels Co. (West Virginia), 841

N.E.2d 1133, 1137 (Ind. 2006). Statements of facts are admissible, as they are not legal

conclusions. See, e.g., Cincinnati SMSA Ltd. P’ship, 2009 WL 2783705, at *5

(explaining several admissible statements of facts).

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A trend exists “to allow expert opinion testimony even on the ultimate issue of the

case, so long as the testimony concerns matters which are not within the common

knowledge and experience of ordinary persons and will aid the trier of fact.” Kelly, 825

N.E.2d at 864 (quoting Vaughn, 777 N.E.2d at 1122–123). To this effect, Indiana trial

courts are generally granted broad discretion in admitting expert testimony. See ‘Norfolk

S. Ry. Co. v. Est. of Wagers, 833 N.E.2d 93, 100–01 (Ind. Ct. App. 2005), trans. denied.

This discretion is such that, in bench trials, the Court may admit expert testimony that

includes legal conclusions, so long as the Court expressly ignores such conclusions in

its decision-making. See, e.g., Major v. OEC-Diasonics, Inc., 743 N.E.2d 276, 285 (Ind.

Ct. App. 2001); accord Kelly, 825 N.E.2d at 865 n.6 (indicating that “part of [the]

justification for finding no error” in Major “was the case was tried to the bench, and the

court expressly stated it would ignore the . . . legal conclusions if the court disagreed”).

The Court notes initially that its qualification rulings have narrowed this inquiry. The

Court analyzes the remaining text and the several contested statements appearing

therein. In doing so, the Court finds that Williams offers inadmissible legal conclusions at

various points in what remains of his reports. Testimony on any interpretation of Indiana

statutes, regulations, case law, or compliance thereof will be disregarded, as these

amount to legal conclusions and are well within the bench’s expertise. For example, the

conclusion in the rebuttal report that “[t]his interpretation aligns with the statute’s plain

language requiring ‘public transportation’ services . . .” will be disregarded, as it provides

the expert’s interpretation of Indiana Code § 6-2.5-5-27. (Rebuttal Report § 5.6.0.3.) The

same could be said of other conclusions that by their own terms venture into interpretation

of Indiana Code. (See, e.g., Rebuttal Report §§ 5.6.0.1 (discussing the statutory

20

requirement that the “physical object be used ‘in providing public transportation for

persons or property’”), 6.2.0.2 (“Indiana Code classifies NIPSCO using service-oriented

terminology . . . rather than transportation language . . . .”).)

Any conclusions made by Williams that apply relevant law to the facts of the

case, or that state how the case should be decided, will also be disregarded. For

example, the conclusion by Williams that the relevant legal framework describes

NIPSCO’s functions in terms of service provision rather than transportation activities will

be disregarded, as such a conclusion requires both an interpretation of Indiana law and

an application to the facts of the case. (See Opening Report § 4.4.0.3.) Additionally,

testimony such as “[the Department]’s denial of the transportation exemption . . . should

be upheld” or “the equipment for which the exemption is claimed is not eligible, and [the

Department]’s denial should be upheld” will be disregarded, as this testimony seeks to

opine on how the case should be decided. (Rebuttal Report §§ 2.7.0.1, 6.4.0.2.)

The Court finds, however, that Williams opines on ultimate issues as well. In

contrast with the above testimony, testimony such as “electricity operates according to

physical principles that are fundamentally distinct from transportation systems,” or the

“physics of transmission line operation involve complex electromagnetic interactions

that are fundamentally different from the mechanical systems used to transport goods or

people,” will be retained. (Opening Report §§ 1.0.0.3, 3.3.3.2.) This testimony and

others like it, which aims to describe the nature of electricity, does not seek to interpret

the law, apply facts to law, or declare how a case should be decided. The same is true

of statements like, “[i]n my professional opinion, when customers purchase electricity

from NIPSCO, they are buying the service of having electrical energy available at their

21

location when needed, rather than purchasing a transported commodity.” (Opening

Report § 1.0.0.5.) This statement merely recounts Williams’ belief that customers buy a

service rather than a commodity.

Additionally, there are several points where Williams discusses that NIPSCO

does not engage in the physical transportation of goods and people or transportation

services but rather provides electricity service through electromagnetic energy

transmission and distribution.10 The Court finds that such statements are merely

opinions about ultimate issues of fact, describing Williams’ opinions about NIPSCO’s

services. Any seeming proximity to the statutory language is incidental and not

determinative. Williams is allowed to opine on ultimate issues of fact—he’s just not

allowed to testify about legal conclusions.

In sum, the Court decides that portions of Williams’ testimony amount to legal

conclusions and will be disregarded when deciding the cross-motions for summary

judgment. The Court need not decide now which specific items to exclude; rather, when

the Court decides the summary judgment motions, it will simply ignore any and all legal

conclusions. See Major, 743 N.E.2d at 285; Kelly, 825 N.E.2d at 865 n.6. While

NIPSCO asserts that Williams’ reports are replete with inadmissible legal conclusions

10

See, e.g., Opening Report § 1.0.0.2 (“[I]t is my professional engineering opinion that NIPSCO does not engage in transportation services, but rather provides electricity service through electromagnetic energy transmission and distribution.”), § 1.0.0.7 (“It is my professional engineering opinion that NIPSCO provides electricity service through electromagnetic energy transmission and distribution which operates according to fundamentally different principles than the physical transportation of goods or people.”); § 5.0.0.1 (“Based on my professional engineering analysis, NIPSCO’s operations involve electromagnetic energy transmission and distribution services rather than the physical transportation of goods or people.”); § 5.6.0.2 (“It is my professional engineering opinion that NIPSCO provides electricity service through electromagnetic energy transmission and distribution which operates according to fundamentally different principles than the physical transportation of goods or people.”); § 5.6.0.3 (“[I]t is my professional engineering opinion that the equipment purchases for which NIPSCO seeks tax exemption are integral to providing electricity service through electromagnetic energy transmission and distribution operations. These technical characteristics distinguish NIPSCO’s operations from the physical transportation of goods or people.”).

22

such that the entirety of his reports should be stricken, the Court finds that the

remainder of Williams’ reports and testimony continues to offer assistance to the trier of

fact as background and context, notwithstanding his legal conclusions. To the extent

that Williams’ reports and related testimony are in the form of legal conclusions, though,

the Court will disregard them.

CONCLUSION

The Court finds that expert witness Williams is qualified under Rule 702(a) to

offer testimony describing the general nature of electricity (Category 1), which the Court

finds is also based on reliable scientific principles. And, while he can testify generally

about the electric industry, NIPSCO’s company overview, the functioning of regional

grid networks, the design, operation, or coordination of electric transmission systems,

and the electrical utility regulatory framework (Category 2), he has not been shown to

be qualified to interpret the meaning of, or apply knowledge gained from, specific

regulatory instruments. Of the remaining text, the Court finds that Williams offers

several legal conclusions that Rule 704(b) disallows.

In light of this, NIPSCO’s Motion to Exclude Testimony of Putative Expert John A.

Williams is GRANTED IN PART and DENIED IN PART. The portions of Williams

reports where he interprets the meaning of, or applies knowledge gained from, specific

regulatory instruments—including but not limited to NIPSCO’s FERC Form 1 Annual

Report of Major Electric Utilities, Licensees and Others and Supplemental Form 3-Q

Quarterly Financial Report, FERC Form 1 Electric Energy Account and Monthly

Transmission System Peak Load data, FERC Electric Quarterly Report transaction

summaries, FERC Form 566, the FERC Uniform System of Accounts, NERC reliability

23

standards, the EIA-861 and EIA-923 forms, and IURC tariff schedules—are STRICKEN.

The legal conclusions in Williams’ reports are also STRICKEN.

SO ORDERED this 31st day of August 2026.

Justin L. McAdam

Judge, Indiana Tax Court

Distribution:

Randal J. Kaltenmark, Steven A. Baldwin, Darrick J. Hooker, Jefferson S. Garn,

Michelle R. Wyatt, Shelby M. Stouder

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