Risk Management Expert’s Testimony on the Required Team Composition Excluded

Andre Pauwels, the Plaintiff, filed an unjust enrichment claim against The Bank of New York Mellon Corporation and The Bank of New York Mellon, collectively referred to as “BNYM.”

In short, Pauwels, who previously served as a consultant for BNYM, alleged that BNYM was unjustly enriched by its continued use of his “proprietary computational model”—the Pauwels Model—which is used to analyze proposed tax-equity investments in wind energy projects and monitor the investment BNYM chose to pursue.

Pauwels sought to quantify the amount by which BNYM was unjustly enriched through the expert testimony of Slim Bentami. Bentami, in his Report and proposed testimony, opined on the cost BNYM, or a similar large bank, would expend to recreate the Pauwels Model from scratch. BNYM filed a motion to exclude Bentami’s testimony from trial.

Risk Management Expert Witness

Slim Bentami has over 30 years of experience in the finance industry. He previously held various leadership roles within the Risk Division at Goldman Sachs, where he was responsible for “ensuring that the models used by the firm were fit for purpose and error free.”

Discover more cases with Slim Bentami as an expert witness by ordering his comprehensive Expert Witness Profile report.

Discussion by the Court

BNYM argued, in short, that Bentami’s report and anticipated testimony (1) support a theory of damages which is not cognizable as a matter of New York law, (2) rely on insufficient facts or data; and (3) use an unreliable methodology.

BNYM primarily attacked Bentami’s relatively terse explanation of why various staff members would be necessary as a part of his “hybrid equivalent” team replicating the Pauwels Model in-house.

Bentami justifies the composition of such a team as follows:

“Based on my experience and analysis, I would expect a team of quantitative modeling professionals of various levels to be dedicated to the development of a Pauwels Model equivalent from scratch. In my opinion, such a team would likely consist of (1) one Managing Director (“MD”) level person experienced with this type of investment; (2) two senior Vice President (“VP”) level persons experienced with this type of investment as well as with enterprise systems and processes; and (3) three Associate level staff who would perform the brunt of the development. Such staff would typically be part of a structuring modeling team and/or quantitative development team. The necessity for three associate-level staff follows from the need for redundancy and for cross-validation of work.”

I. Bentami’s Report Is Relevant Under Rule 702

BNYM first argued that Bentami’s report and testimony should be “excluded because they merely attempt to quantify a theory of damages that is not recoverable as a matter of law.”

Pauwels contended that Bentami’s opinions speak to the “value of the thing that BNYM took from Plaintiff” by quantifying the “development cost” of the Pauwels Model.

It should be noted that Pauwels performed consulting work for BNYM from 2014 to 2017. Pauwels stopped monitoring BNYM’s investments in September 2017, when BNYM replaced him with Deloitte LLP, Deloitte Tax LLP, and Deloitte USA LLP (together, “Deloitte”). The parties disputed the extent to which Deloitte used the Pauwels Model when it took over this monitoring work. 

Bentami is offering an opinion on the costs that would be incurred if BNYM or an equivalent bank sought to replicate the Pauwels Model. He did not opine on the costs Pauwels himself incurred to create the Pauwels Model or the third-party costs BNYM avoided through the use of the Pauwels Model. Notably, as BNYM has argued, Bentami’s valuation “does not even correspond to . . . the costs that BNY[M] purportedly avoided paying to Deloitte in performing the ongoing investment monitoring work.”

BNYM attempted to preclude admission of Bentami’s report and testimony on the basis that it does not, and cannot, accurately reflect BNYM’s avoided costs through a reduction in the work done by Deloitte. Bentami’s report, however, clearly indicated that it attempted to measure BNYM’s own cost to replicate the Pauwels Model, rather than its avoided costs with respect to Deloitte.

Accordingly, the Court found that Bentami’s opinions could support a legally cognizable theory of damages.

II. Bentami’s Report Should Be Excluded as Unreliable under Rule 702

Despite Bentami’s substantial experience developing financial models inside large financial institutions, Bentami did not explain with any specificity how his experience led him to reach certain conclusions.

Bentami provided a relatively terse explanation of why various staff members would be necessary as a part of his “hybrid equivalent” team replicating the Pauwels Model in-house. 

For example, Bentami includes no detail as to why a “Managing Director” and two “senior Vice Presidents” would be necessary to recreate a model one man created himself.  And without the benefit of any explanation from Bentami, the Court did not see how it “follows” that three associate level staff would also be necessary to satisfy the need for “redundancy and cross-validation of work.”

Bentami’s estimation of the compensation paid to each of these team members was accomplished through a similarly superficial exercise. He simply stated that, “based on his experience and analysis, he estimated the team compensation costs,” for which he lists annual compensation figures.

Bentami’s unexplained equivalence between one hour of Pauwels’ work and one hour of his “hybrid equivalent” team of seven people was also puzzling. 

Bentami’s conclusions regarding the length of time an in-house team would spend developing an equivalent to the Pauwels Model appeared to be based exclusively on unsupported, approximately one-to-one equivalence between an hour of Pauwels’ time and an hour of hybrid-equivalent team time. He offered no indication as to why his experience would lead him to opine that this rough equivalence in productivity would be sufficient as even a crude proxy for the work necessary to replicate the Pauwels Model.

It should be noted that Bentami only reviewed two out of the twelve Pauwels Model spreadsheets created to analyze BNYM’s investments.

Held

The Court granted BNYM’s motion to strike Slim Bentami’s report and preclude his testimony.

Key Takeaway:

Bentami did not offer even anecdotal evidence as to why such a team composition would be necessary or why this team would work a “hybrid-equivalent” number of hours to Pauwels, through specific reference to his own experience or what is customary in the industry. An expert basing his opinion solely on experience must do more than aver conclusorily that his experience led to his opinion. Bentami provided no detail to support his assumptions beyond a generalized reference to his expertise. And he did not explain “how his experience supports his conclusion” as to the required team composition, compensation, or time spent on the replication project.

Because critical steps of Bentami’s methodology are supported by nothing more than his “ipse dixit,” the Court found his methodology to be unreliable.

Case Details:

Case Caption:	Pauwels V. Bank Of New York Mellon Corporation
Docket Number:	1:19cv2313
Court Name:	United States District Court, New York Southern
Order Date:	October 31, 2025