Cassata v. Michael Macrina Architect, P.C.

Issue

When an associate copies an outside lawyer's brief that contains fabricated citations into her own opposition papers, who is sanctionable under 22 NYCRR 130-1.1: the associate alone, or also her supervising attorney and the firm?

Rule

Justice Linda Kevins applied 22 NYCRR 130-1.1, which permits a court to award costs and to impose financial sanctions for frivolous conduct, defined at 130-1.1(c) to include conduct completely without merit in law and the assertion of material factual statements that are false, and which directs the court to consider whether the conduct continued after its lack of basis was brought to counsel's attention. She also found violations of the New York Rules of Professional Conduct, 22 NYCRR 1200.0, at Rule 1.1 competence including comment 8 on keeping abreast of technology, Rule 1.3 diligence, Rule 3.1 non-meritorious contentions, Rule 3.3 candor toward the tribunal, and Rule 5.1 the supervisory duties of a firm and of a lawyer with direct supervisory authority. She acted under 22 NYCRR 100.3(D)(2), which requires a judge who receives information of a substantial likelihood of a substantial violation to take appropriate action, and under the court's inherent power. For calibrating the sanction she adopted the three factors set out in Mattox v. Production Innovations Research, LLC: verification and inquiry, candor and correction, and accountability and supervision.

Application

The underlying case concerns a house at Westhampton Dunes whose wood framing collapsed. Plaintiffs moved to strike the defendant architect's thirty-six affirmative defenses. The opposition filed by associate Maria-Eleni Kiousenterlis of Milber Makris Plousadis and Seiden cited two cases that do not exist, Harris v. Seward Park Housing Corp. and DiLorenzo v. D.C. and D. Transportation Corp.; contained a quotation attributed to Harris that appears only in her brief and in the brief she had copied; cited New York University v. Continental Insurance Co. and Becker v. Elm Air Conditioning Corp. for propositions they do not support; and copied entire portions of a brief filed by another lawyer in an unrelated case, without attribution, that a New York County judge had already condemned for citing non-existent cases. Plaintiffs' counsel identified all of this in reply papers and letters. At the December 22, 2025 hearing, Kiousenterlis and supervising partner Thomas M. Fleming II conceded all six allegations and appeared sincerely sorry, but Kiousenterlis denied using AI, saying she had found a brief on Westlaw and incorporated it without verifying anything. The court was not persuaded by the denial and said the copy-and-paste account is barely more flattering than the AI account. On supervision, the court found Fleming could not adequately supervise Kiousenterlis's use of the firm's newly acquired AI-enhanced Westlaw tool because he conceded he did not really know how to use AI tools, and it found a hole in the firm's policy: the handbook addressed the use of AI but not the copying of someone else's AI-tainted brief, a gap Fleming candidly admitted was possible when the court put it to him. On candor, the court found that neither Kiousenterlis nor Fleming was forthcoming in the first instance, that her November 25 letter used the words "citation inaccuracies" and "alleged" without identifying the sourcing, the plagiarism, the non-existent cases, or the fabricated quotation, and that Fleming and another senior member of the firm helped revise that letter and let it improperly advance further merits argument. The court also considered the reliability data behind its ruling, citing the New York State Unified Court System advisory committee report of December 2025 and the underlying Stanford study finding that the Lexis product hallucinated in 17 percent of responses and the Westlaw product in 33 percent. It attached a twelve page chart of AI hallucination sanctions decisions from across the country as Exhibit A and incorporated it by reference.

Conclusion

Justice Kevins struck the November 17, 2025 opposition; fined Kiousenterlis $1,000 and Fleming $1,000, each payable to the Lawyers' Fund for Client Protection; and ordered the firm, Milber Makris Plousadis and Seiden, to pay $8,000 in reasonable attorneys' fees, costs, and expenses to plaintiffs' counsel Ruskin Moscou Faltischek, with the firm to serve the decision on its client. She expressly declined to refer any of them to the Grievance or Disciplinary Committee and stopped short of ordering AI education, instead highly recommending CLE and warning that a future sanction may not be as lenient. This is a trial-level decision, published as 2026 NY Slip Op 26014; it is persuasive rather than binding.

It is incredible that an attorney would "copy and paste" from someone else's brief without verifying their sources, citations, quotations, propositions of law, and reading the ultimate court decision upon which the brief was submitted, and ultimately reviewed and considered.

Justice Linda Kevins, explaining why she did not credit counsel's denial that she used AI

In the instant matter and considering everything set forth herein, this Court does not believe that appropriate action includes referring counsel to the Grievance/Disciplinary Committee.

Justice Kevins, declining to refer any of the three sanctioned parties for discipline

the Law Office of Milber Makris Plousadis & Seiden, LLP shall pay reasonable attorneys' fees, costs, and expenses in the amount of $8,000.00 payable to the attorneys for plaintiff, Ruskin Moscou Faltischek, P.C.

Justice Kevins, from the decretal paragraphs imposing sanctions on the firm

Why it matters. Cassata is the case to cite for institutional exposure. It reaches past the associate who signed to the partner who supervised and the firm whose name was on the papers, and it holds that an AI use policy is not enough if it does not cover copying someone else's AI-tainted work. It also shows a court finding serious frivolous conduct and still declining to make a disciplinary referral, which is a useful counterweight to the assumption that referral is automatic.

Read the full opinion on CourtListener

This summary was written from the opinion itself. Every quotation above was located in the text of the decision it is attributed to. It is a summary for public education and is not legal advice.

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