Hamrit v. Citigroup Global Markets, Inc.

UNITED STATES DISTRICT COURT

SOUTHERN DISTRICT OF NEW YORK

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:

HOUSSAM EDDINE HAMRIT, :

:

Plaintiff, :

: 22 Civ. 10443 (JPC)

-v- :

: OPINION AND

CITIGROUP GLOBAL MARKETS, INC., et al., : ORDER

:

Defendants. :

:

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JOHN P. CRONAN, United States District Judge:

Defendants Citigroup Global Markets, Inc., Citi Personal Wealth Management, and

Citigroup, Inc. (collectively, “Citigroup”) move in limine to exclude the proffered expert testimony

of Larry F. Stewart. Pro se Plaintiff Houssam Eddine Hamrit seeks to have the Court consider at

trial expert conclusions from Stewart on the issue of whether he entered into an arbitration

agreement with Citigroup when his online brokerage account was opened. For the following

reasons, the Court grants Citigroup’s motion.

I. Background

In its March 26, 2024 Opinion on Citigroup’s pending motion to compel arbitration, the

Court outlined the background of this dispute. See Hamrit v. Citigroup Glob. Mkts., Inc., No. 22

Civ. 10443 (JPC), 2024 WL 1312254 (S.D.N.Y. Mar. 26, 2024). The Court assumes the parties’

familiarity with that background. In that Opinion, the Court concluded that Hamrit had come

forward with some evidence to raise a dispute of material fact on whether the parties agreed to

arbitrate and that Citigroup failed to cast doubt on the plausibility of that evidence, and therefore

ordered a trial on that limited issue. Id. at *9. In reaching that result, the Court noted that Citigroup

had “attack[ed] Stewart’s qualifications and ask[ed] the Court to disregard his report,” which was

part of Hamrit’s opposition to Citigroup’s motion to compel. Id. at *6 n.8. The Court did not rely

on Stewart’s conclusions in the Opinion, but noted that Citigroup would have “the opportunity to

challenge Stewart’s ability to provide expert testimony [at trial], should Hamrit wish to call Stewart

as a witness.” Id. Following the March 26, 2024 Opinion, the parties conducted limited discovery

in preparation for a bench trial on whether Hamrit entered into an arbitration agreement with

Citigroup.

On August 29, 2024, Citigroup moved in limine to exclude Stewart’s anticipated testimony

under Federal Rule of Evidence 702. Dkt. 85 (“Motion”). Hamrit filed his opposition on

September 12, 2024. Dkt. 90 (“Opposition”).1 Citigroup filed a reply declaration on September

19, 2024. Dkt. 91 (“Reply”). “Because [the defendants’] Daubert challenge[ was] raised just prior

to trial and this trial was conducted as a bench trial, the court elected to hear the Daubert proof

during the trial itself.” Howard Univ. v. Borders, No. 20 Civ. 4716 (LJL), 2022 WL 11817721, at

*10 (S.D.N.Y. Oct. 20, 2022) (internal quotation marks omitted). “Although a court has general

discretion to hear expert testimony and reserve [ruling] on a Daubert motion until the conclusion

of a bench trial, it still must perform a Rule 702 and Daubert analysis before it relies upon expert

testimony.” Town & Country Linen Corp. v. Ingenious Designs LLC, No. 18 Civ. 5075 (LJL),

2022 WL 2757643, at *3 (S.D.N.Y. July 14, 2022). Trial in this matter commenced on October

1 The Court construes Hamrit’s pro se opposition to Citigroup’s motion liberally and

interprets his filings and arguments in court to raise the “strongest arguments that they suggest.”

Triestman v. Fed. Bureau of Prisons, 470 F.3d 471, 474 (2d Cir. 2006) (per curiam) (internal

quotation marks omitted) (collecting cases); accord Rahmankulov v. United States, Nos. 23 Civ.

3206 (RA), 20 Cr. 653 (RA), 2023 WL 3303949, at *1 (S.D.N.Y. May 8, 2023) (explaining that

while the Court must construe pro se pleadings liberally, “a pro se litigant is not exempt ‘from

compliance with relevant rules of procedural and substantive law’” (quoting Triestman, 470 F.3d

at 477)).

22, 2024, and the Court, reserving a ruling on the pending motion in limine, heard Stewart’s

testimony on October 25, 2024.2

Hamrit seeks to offer expert conclusions from Stewart that fall into two buckets. First,

Stewart testified that the security standards Citigroup employed did not align with those of the

National Institute of Standards and Technology (“NIST”) for high value transactions. Trial Tr. at

299:17-300:4, 319:6-11; see also Pl. Exh. 9 (“Stewart Report”) at 12 (citing NIST’s Digital

Identity Guidelines). Second, Stewart concluded that Citigroup’s system did not truly verify

Hamrit’s identity given discrepancies in the account opening documentation.3 Trial Tr. at 318:23-

319:5; accord Stewart Report at 14 (“[I]t is my expert opinion that in light of the inadequacies and

abnormalities in the evidence as enumerated above, the [Account Application and Client

Agreement] are not reliable as conclusive proof of Mr. Hamrit’s electronic signature.”).

II. Legal Standard

Federal Rule of Evidence 702 provides:

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 proponent

demonstrates to the court that it is more likely than not that:

(a) 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;

2 The transcript of the bench trial is at Docket Numbers 100, 102, and 104. In this Opinion,

the trial transcripts are collectively referred to as “Trial Tr.” and the parties’ trial exhibits are

referred to as “Pl. Exhs.” and “Defts. Exhs.”

In addition to Stewart’s testimony, Hamrit sought to introduce into evidence several

declarations from Stewart and Stewart’s report. See Pl. Exhs. 8, 9, 22, 23. The Court accepted

these exhibits contingent on whatever weight they should receive following the Court’s resolution

of Citigroup’s motion in limine. Trial Tr. at 302:23-25; see also id. at 326:14-17.

3 According to Citigroup, Hamrit completed and executed the Account Application and

Client Agreement when he created his online brokerage account on May 3, 2020. The Account

Application and Client Agreement was admitted at trial as Defendants’ Exhibit 1. At the core of

the trial is whether Hamrit agreed to an arbitration clause contained at section 6 of that document.

(b) the testimony is based on sufficient facts or data;

(c) the testimony is the product of reliable principles and methods; and

(d) the expert’s opinion reflects a reliable application of the principles and

methods to the facts of the case.

Fed. R. Evid. 702. “The fundamental requirements are thus that such evidence be relevant and

reliable.” United States v. Jones, 965 F.3d 149, 161 (2d Cir. 2020) (citing Daubert v. Merrell Dow

Pharms., Inc., 509 U.S. 579 (1993); Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999)).

“[T]he proponent of expert testimony has the burden of establishing by a preponderance of

the evidence that the admissibility requirements of Rule 702 are satisfied,” although “the district

court is the ultimate gatekeeper.” Id. (internal quotation marks omitted). This role requires the

district court to find that any admitted expert testimony “is not only relevant, but reliable.”

Daubert, 509 U.S. at 589. “Relevancy is determined by whether the proffered evidence ‘has any

tendency to make the existence of any fact that is of consequence to the determination of the action

more probable or less probable.’” Town & Country Linen Corp., 2022 WL 2757643, at *2 (quoting

Amorgianos v. Amtrak, 303 F.3d 256, 265 (2d Cir. 2002)). Reliability, meanwhile, encompasses

“a number of factors . . . that district courts may consider,” and is designed to be a flexible standard,

“focus[ed] on the principles and methodology employed by the expert, without regard to the

conclusions the expert has reached or the district court’s belief as to the correctness of those

conclusions.” Amorgianos, 303 F.3d at 266. “[W]hen an expert opinion is based on data, a

methodology, or studies that are simply inadequate to support the conclusions reached, Daubert

and Rule 702 mandate the exclusion of that unreliable opinion testimony.” Id.

III. Discussion

Citigroup argues that Stewart is not qualified to offer an opinion regarding the financial

technology matters relevant to whether Hamrit electronically executed the arbitration agreement,

Motion at 4-5, and also contends that Stewart’s testimony would not be helpful to the trier of fact

as his opinions did not stem from any specialized expertise but instead merely convey lay

observations, id. at 6-7.

A. Qualifications

“Rule 702 requires a trial court to make an initial determination as to whether the proposed

witness qualifies as an expert.” Am. Empire Surplus Lines Ins. Co. v. J.R. Contracting & Env’t

Consulting, Inc., No. 23 Civ. 4942 (AT) (SDA), --- F. Supp. 3d ---, 2024 WL 3638329, at *5

(S.D.N.Y. Aug. 2, 2024) (internal quotation marks omitted). “As a threshold matter, trial courts

must consider whether the witness is qualified by knowledge, skill, experience, training, or

education to render his or her opinions as an expert, before reaching an analysis of the testimony

itself.” Vale v. United States, 673 F. App’x 114, 116 (2d Cir. 2016).

Citigroup contends that Stewart is not qualified to offer an expert opinion concerning

whether Hamrit electronically executed an arbitration agreement because he “has no demonstrated

expertise in cybersecurity, financial technology, opening of online accounts, or computer science

generally.” Motion at 5. Instead, Citigroup maintains that Stewart’s “expertise is limited to

handwriting, ink, document analysis and crime scene investigations.” Id. “To determine whether

a witness qualifies as an expert, courts compare the area in which the witness has superior

knowledge, education, experience, or skill with the subject matter of the proffered testimony.”

United States v. Tin Yat Chin, 371 F.3d 31, 40 (2d Cir. 2004).

At trial, Stewart explained that he is “a forensic scientist that specializes in chemistry and

document security.” Trial Tr. at 282:5-7. And Stewart does appear to have expertise in these areas

from his experience, training, and education. See id. at 282:8-283:6 (Stewart testifying about his

education, certification, and membership in professional associations), 283:24-284:19 (Stewart

describing his training, publications, and membership on boards in this field). When questioned

by Citigroup’s counsel on voir dire, Stewart further testified that, in his prior role as a laboratory

director with the United States Secret Service,4 he supervised the “digital evidence laboratory” and

reviewed analytic work on that subject, although he did not perform the primary analysis. Id. at

288:15-25.

While Citigroup correctly notes Stewart’s lack of expertise in computer science, financial

technology, or cybersecurity, Hamrit offered Stewart at trial as an expert in “document security.”

Id. at 286:17-19; see also Opposition at 4-7. When asked what he understood the term “document

security” to mean, Stewart testified that “[t]here are a number of levels of security that are attached

to documents at the federal level which is where I work. NIST is one of the main ones that

designate the security involved in documents. And also a group called FinCEN. Those are in

addition to the FinTech he’s mentioning, which is mainly for bank fraud situations.” Trial Tr. at

291:10-19. Stewart explained that at the Secret Service, he dealt with document security issues

and received training in “all aspects of documents from passports to personal documents like

driver’s licenses and identity documents that can be created either online or manually using

devices,” as well as in investigating financial institution fraud involving digital systems. Id. at

292:4-19. Stewart’s most recent formal training in this area, though, was in the 1990s. Id. at

292:21-25. Nonetheless, “[e]ven if a proposed expert lacks formal training in a given area, he may

still have ‘practical experience’ or ‘specialized knowledge’ qualifying him to give opinion

testimony under Rule 702.” Lickteig v. Cerberus Cap. Mgmt., L.P., 589 F. Supp. 3d 302, 328

(S.D.N.Y. 2022).

4 According to Stewart’s resume, he held various positions with the Secret Service from

July 1982 through June 2005. Pl. Exh. 8 (“Stewart July 28, 2023 Declaration”) at 57.

The parties disagree on whether Stewart’s experiences qualify him to offer an expert

opinion on the narrow issue of the trial: whether Hamrit electronically executed an arbitration

agreement with Citigroup when his online brokerage account was opened. Compare Motion at 5,

with Opposition at 6-7. In the end, the Court need not determine the full reach of Stewart’s

expertise. As will be explained at infra III.B, the opinions Stewart seeks to offer do not survive

Rule 702 on relevance or reliability grounds, and thus must be excluded regardless of his expert

qualifications. The Court therefore will assume without deciding that Stewart has expertise in the

proffered field of “document security” for Rule 702 purposes.

The Court emphasizes one caveat to this assumption, however. A key piece of evidence in

this case is a document called a ThreatMetrix report. See Defts. Exh. 4. One of Citigroup’s

witnesses at trial, a Citigroup fraud risk officer named Eustacio Valfre, explained that this report

captures “[e]ach digital session” that a client has on Citigroup’s online platform and that the report

“has a bunch of different data points that [Citigroup’s fraud officers] review” when assessing fraud

risk. Trial Tr. at 94:5-95:3. Valfre testified that these reports include certain “digital evidence,”

such as the “time that a person may have logged in on their account, [the] account user ID that was

used, the time that it was accessed, what was done within that session, and how that session was

authenticated.” Id. at 96:4-7. The ThreatMetrix report captures “session information, such as a

unique session ID[,] . . . geo location, which would be IP address, true IP address, and DNS IP

address[,] . . . latitude and longitude[,] . . . transaction information, what was done within that

session, if there was any type of transfers, and such. And then you have an authentication [the

user] used, or any challenges, and how they were passed.” Id. at 96:8-14. Valfre also testified that

Citigroup’s fraud risk officers receive six weeks of training on the ThreatMetrix product and other

fraud prevention tools, which enables them to “review and analyze data that [Citigroup is] seeing

in our digital space,” and that the training includes “the usage and the review of the data fields that

we receive, and using [Citigroup’s] tools, and how to interpret that information.” Id. at 90:6-23,

93:7-17.

It is unclear whether Stewart sought to offer his opinions based on the ThreatMetrix report,

or otherwise to opine on the contents of the report. Indeed, Stewart does not identify the

ThreatMetrix report in his own purported expert report among the materials he reviewed in arriving

at his conclusions, see Stewart Report at 1-2,5 nor does he reference the ThreatMetrix report in his

report’s “Observations,” see id. at 2-14. Yet, at trial, Stewart testified that he reviewed the

ThreatMetrix report in preparing his report. Trial Tr. at 296:6-9. To be sure, however, Stewart

lacks “knowledge, skill, experience, training, or education,” Fed. R. Evid. 702, to offer opinions

based on the ThreatMetrix report or concerning its contents, as the Court ruled at trial, Trial. Tr.

at 306:11-307:6.

“[B]ecause a witness qualifies as an expert with respect to certain matters or areas of

knowledge, it by no means follows that he or she is qualified to express expert opinions as to other

fields.” Nimely v. City of New York, 414 F.3d 381, 399 n.13 (2d Cir. 2005). And Stewart plainly

is not qualified to offer an expert opinion regarding the ThreatMetrix report. During voir dire,

Stewart testified that he has never received any training concerning ThreatMetrix, has never

offered an opinion concerning ThreatMetrix, and has never drafted a report concerning

ThreatMetrix. Trial Tr. at 289:5-13. Nor did Hamrit otherwise offer any information indicating

Stewart’s training or experience with regard to ThreatMetrix. Given Stewart’s testimony, the

5 Hamrit’s Opposition also indicates that Stewart had not reviewed the ThreatMetrix report

prior to preparing his report for this case. See Opposition at 9 (complaining that “Mr. Stewart must

be allowed the opportunity to review, analyze and testify about” the ThreatMetrix report); see also

Reply, Exhs. B, C (establishing that, contrary to Hamrit’s gripes, the ThreatMetrix report was

disclosed during discovery).

limits of his training and experience, and his lack of familiarity with the ThreatMetrix product, the

Court reiterates its determination that Stewart is not qualified to offer testimony that would aid the

Court’s assessment of the ThreatMetrix report. See id. at 306:13-307:6 (the Court observing, after

hearing Stewart’s testimony, that Stewart “very clearly testified that he has no training concerning

ThreatMetrix, [has] not offered any opinion in the past” concerning ThreatMetrix, and has “never

drafted a report concerning” ThreatMetrix, and thus “[a]nything Mr. Stewart would testify about

that report is something that [the Court is] able to derive from the report that’s already in

evidence”).

The Court acknowledges that “[i]f the expert has educational and experiential

qualifications in a general field closely related to the subject matter in question, the court will not

exclude the testimony solely on the ground that the witness lacks expertise in the specialized areas

that are directly pertinent.” Am. Empire Surplus Lines Ins. Co, 2024 WL 3638329, at *5 (internal

quotation marks omitted). But to be sure, that is not the case when it comes to the ThreatMetrix

report. And the Court’s focus remains on “whether the expert’s knowledge of the subject is such

that his opinion will likely assist the trier of fact in arriving at the truth.” Id. (internal quotation

marks omitted). Stewart’s purported expertise in “document security” was devoid of any

knowledge or training that would allow him to opine on the probative value of the information in

a technical product like the ThreatMetrix report that captures a variety of pieces of digital evidence

and requires specialized training to properly understand and interpret.

In sum, the Court will assume without deciding that Stewart possesses expert qualification

to testify on matters in this case, with the understanding that he may not base any opinions on the

ThreatMetrix report or opine on its contents.

B. Relevance and Reliability

Even assuming arguendo Stewart’s expertise in document security, his proffered expert

testimony fails the relevance and reliability requirements of Rule 702. Starting with relevance,

Rule 702(a) requires that the expert’s knowledge “help the trier of fact to understand the evidence

or to determine a fact in issue.” Fed. R. Evid. 702(a). This requirement “goes primarily to

relevance.” In re Fosamax Prods. Liab. Litig., 645 F. Supp. 2d 164, 173 (S.D.N.Y. 2009) (citing

Daubert, 590 U.S. at 591). But “expert testimony is not helpful if it simply addresses ‘lay matters

which the [finder of fact] is capable of understanding and deciding without the expert’s help.’” Id.

(quoting United States v. Lumpkin, 192 F.3d 280, 289 (2d Cir. 1999)). And “[a] court should not

admit expert testimony that is ‘directed solely to lay matters which a [finder of fact] is capable of

understanding and deciding without the expert’s help.’” Pacific Life Ins. Co. v. Bank of N.Y.

Mellon, 571 F. Supp. 3d 106, 114 (S.D.N.Y. 2021) (quoting United States v. Mulder, 273 F.3d 91,

104 (2d Cir. 2001)).

Almost all of Stewart’s proffered testimony falls into this category of matters that the Court

is fully capable of understanding without assistance from an expert. Stewart explained that his

methodology entailed “first examining the submitted Account Application and Client Agreement

followed by an analysis of the submitted supportive documentation and self-obtained data. The

results were then compared and presented here.” Stewart Report at 2; Stewart July 28, 2023

Declaration ¶ 7. In other words, Stewart looked at two documents and observed that some of the

information in each was different. From this method, Stewart concluded that Citigroup’s system

did not “truly verif[y] the identity of Mr. Hamrit,” Trial Tr. at 318:23-319:5, and that the Account

Application and Client Agreement “are not reliable as conclusive proof of Mr. Hamrit’s electronic

signature,” Stewart Report at 14.

The Court, of course, is well-equipped to do the same analysis. It requires no expertise,

for example, to observe that Hamrit’s “residential address at the date of the Account Application

and Client Agreement was different from the residential address stated therein,” that Hamrit’s

“immigration status is different from that stated in the Account Application and Client

Agreement,” or that a document has “different fonts,” contains a “blurred image,” or lacks a

signature. Stewart July 28, 2023 Declaration ¶ 9; see also Stewart Report at 2-10 (providing these

and other examples of discrepancies, such as different spellings of Hamrit’s mother’s maiden name

on the Account Application and Client Agreement and on Hamrit’s birth certificate). These are

simply lay observations concerning the contents of two documents, which in no way rely on

Stewart’s purported expertise in document security. See Pacific Life Ins. Co., 571 F. Supp. 3d at

114. Moreover, this methodology directly led Stewart to draw a conclusion that a layperson,

lacking expertise in document security, would reach: discrepancies between the documents raise a

question of their authenticity. See Atl. Specialty Ins. v. AE Outfitters Retail Co., 970 F. Supp. 2d

278, 291-92 (S.D.N.Y. 2013) (excluding expert testimony on the subject of fire damage on the

grounds that “the mere fact that a fire causes increasing damage the longer it burns is an obvious

statement, and a lay person is entirely capable of reaching this conclusion without the help of an

expert”).

Stewart’s purported opinion that Citigroup did not verify Hamrit’s identity because there

were discrepancies in the account opening documentation, therefore, does not rely on any expertise

but is drawn from lay matters that the Court is “capable of understanding and deciding without the

expert’s help.’” Pacific Life Ins. Co., 571 F. Supp. 3d at 114 (quoting Mulder, 273 F.3d at 104).

Because Stewart’s observations and conclusions in this regard do not “help the [Court] to

understand the evidence or to determine a fact in issue,” Fed. R. Evid. 702(a), they fail the

helpfulness requirement of Rule 702 and are excludable on that basis.

Moreover, Stewart’s proffered expert testimony suffers from reliability concerns. Rule

702(b) requires that an expert’s testimony be “based on sufficient facts or data.” Fed. R. Evid.

702(b). The undisputed evidence at trial, however, makes clear that Stewart’s testimony and

conclusions repeatedly were predicated on insufficient facts and invalid assumptions.

Most significantly, Stewart’s proffered conclusion that Citigroup’s security standards were

insufficient relied on a fundamentally flawed premise as he assumed the absence of biometric

authentication. Stewart testified that Hamrit’s purported account-opening transaction did not

comply with the standards of the NIST for large dollar transactions. Trial Tr. at 299:17-300:4.

Stewart reasoned in his report that Citigroup’s failure to use such standardized measures, like

private encryption keys and electronic signature authentications, undermine confidence that

Hamrit in fact entered into the arbitration agreement. Stewart Report at 10-14. But at trial, when

asked whether he would have concerns with security if someone accessed their account via

“biometrics through using face ID,” Stewart replied, “No. As you add additional security through

face identification or, you know, a two-step process, like they have in a lot of different situations

now, that adds security to it.” Trial Tr. at 300:22-301:7. Stewart remarked, however, that he saw

“no evidence of that being done here.” Id. at 301:7. Stewart later acknowledged on cross-

examination that using face identification to log in in this manner “would be an added measure of

security,” which he would consider to be “pretty strong.” Id. at 313:6-13; see also id. at 319:4-5

(Stewart testifying that he “saw no evidence of multifactor authentication . . . based on what was

provided to [him]”).

Yet, the undisputed evidence at trial established that Hamrit’s account had in place

biometric identification for access and that such access was indeed used when his online brokerage

account was opened. When asked during cross-examination if he had “registered [his] online

accounts so [he] could log in using facial ID,” Hamrit admitted, “I have face ID. Yes, I have face

ID.” Id. at 242:7-12. Hamrit also testified that he had registered his online accounts to use face

identification before May 3, 2020, the date of the transaction opening his brokerage account. Id.

at 242:14-18. Valfre testified that the ThreatMetrix report logged a biometric login during the

digital session in which the brokerage account was opened. Id. at 97:21-25 (“I can see that this

session on 5/3 began with user ID Houssam10, with that unique ID number under column C. And

this was the initial login, and it was a biometric login. It was a face ID so, basically, holding a

phone up or camera, and facial recognition to log in, to authenticate.”), 98:11-13 (“Q. And he

logged in using facial recognition, not using a password; is that correct? A. That’s correct.”). The

ThreatMetrix report itself likewise established that biometric identification was used to initiate that

account-opening session. See Defts. Exh. 4, Rows 103-104 (indicating a face identification login

to begin an online session on May 3, 2020, five minutes before the brokerage account was opened).

Indeed, the ThreatMetrix report is replete with face identification logins. See generally id.

Stewart’s conclusion that Citigroup’s security standards did not meet those of the NIST thus rested

on the faulty assumption that there was no evidence of Hamrit having biometric access to his

accounts or that such biometric access was used to initiate the session when Hamrit’s brokerage

account was opened.

This is not the only instance of Stewart basing his testimony on insufficient or incomplete

information to draw conclusions regarding the authenticity of the records at issue. Stewart testified

about font issues and the “fuzzy” background on the Client Agreement. Trial Tr. at 318:14-17.

Stewart said he was “not sure how that was created, whether it was a cut and paste from another

document or electronically generated by Citigroup. But if it was electronically created, [he] would

ask for an explanation as to why there is a difference in the quality between that and the rest of the

document.” Id. at 318:17-22. Matthew Higman, a Citigroup employee familiar with the bank’s

digital wealth products, testified that this effect occurs because when a customer “signs” their

name by typing it into the agreement, Citigroup takes an image of what they typed to use as the

customer’s “signature” and renders that along with the date they typed in as evidence of signature.

Id. at 33:13-34:21. No evidence at trial contradicted this testimony. While it may be

understandable why Stewart lacked familiarity with Citigroup’s internal procedures, this too

demonstrates that his conclusions relied on insufficient facts and flawed assumptions.

“Where the record indicates that the expert’s analysis rests on faulty assumptions, the trial

court has discretion to exclude his proffered testimony for lack of probative value.” Bank of N.Y.

Mellon Tr. Co., Nat. Ass’n v. Solstice ABS CBO II, Ltd., 910 F. Supp. 2d 629, 649-50 (S.D.N.Y.

2012) (alterations adopted) (collecting cases). Here, Stewart’s failure to base his conclusions on

complete and accurate information severely diminishes any probative value of his testimony. And

in particular, Stewart’s flawed assumption that biometric access was not in place when Hamrit’s

online brokerage account was opened, in the face of overwhelming and undisputed evidence to the

contrary, renders his conclusion about whether Citigroup met the NIST’s standards devoid of any

probative value and require exclusion of that conclusion.

The Court therefore finds that Stewart’s conclusions that Citigroup failed to employ

security standards that aligned with those of the NIST for high value transactions and that

Citigroup’s system did not truly verify Hamrit’s identity do not survive Rule 702(a) and Rule

702(b). The Court thus excludes Stewart’s proffered expert testimony and strikes Hamrit’s

Exhibits 8, 9, 22, and 23 from the trial record.

IV. Conclusion

For these reasons, Citigroup’s motion is granted. Post-trial briefing remains due by January

31, 2025, with optional response briefs due by February 21, 2025. The Clerk of Court is

respectfully directed to close Docket Number 83.

SO ORDERED.

Dated: November 26, 2024 —Vha Lig é

New York, New York JOHN P. CRONAN

United States District Judge

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