AI Hallucination Cases

The Court found two quotations in the Plaintiffs' memorandum that do not appear in the cited federal opinions and ordered counsel to explain and certify review of all cited cases before deciding whether to impose further sanctions.

Counsel Steven A. Feldman repeatedly filed submissions containing AI-generated nonexistent case citations and misattributed quotations. Opposing counsel flagged numerous errors; the Court found fabricated citations and false quotes, concluded counsel acted in bad faith or with conscious avoidance, struck the filings, and entered default judgment against counsel's client Affable Avenue LLC. The Court permitted opposing counsel to apply for attorneys' fees.

By interim order dated March 17, 2025 the court struck defendants' opposition and cross-motion after finding the filings, drafted with AI, contained hallucinated (fabricated) case citations. The court treated the motion as unopposed thereafter.

"This case adds yet another unfortunate chapter to the story of artificial intelligence misuse in the legal profession. Here, Defendants' counsel not only included an AI-hallucinated citation and quotations in the summary judgment brief that led to the filing of this motion for sanctions, but also included multiple new AIhallucinated citations and quotations in Defendants' brief opposing this motion. In other words, counsel relied upon unvetted AI—in his telling, via inadequately supervised colleagues—to defend his use of unvetted AI."

In a later order, the court declined to order any sanctions in "light of counsel's acknowledgment of the fact that the quotations at issue were not independently verified against the actual opinions and acceptance of responsibility and the remedial measures subsequently put in place to avoid a repetition of the errors "

Counsel submitted a response to an Order to Show Cause that included a false quote attributed to none other than Mata v. Avianca, a case about hallucinations.

Counsel confessed having Claude Sonnet 4 to draft a legal submission, which included fabricated quotations from legal authorities. Counsel said he was pressed by time.

After holding that there is "no reason to distinguish between the submission of fabricated cases and the submission of fabricated quotations from real cases. In both postures, the attorney seeks to persuade the Court using legal authority that does not exist", the court held that Mr. Desmarais had violated Rule 11 of the Federal Rules of Civil Procedure by failing to verify the accuracy of the AI-generated content. Counsel was found to have acted in subjective bad faith, as he was aware of the potential for AI to hallucinate legal citations and failed to take corrective action even after the government pointed out the errors.

The court imposed a $1,000 monetary sanction and required Counsel to complete a CLE course on the ethical use of AI in legal practice and notify his client of the issue.