Matter of Bourguignon v. Coordinated Behavioral Health Servs., Inc. does not exist — a fabricated AI citation

In Park v. Kim, a reply brief on appeal to the Second Circuit cited “Matter of Bourguignon v. Coordinated Behavioral Health Servs., Inc.” for a legal proposition central to the appellant's argument. The panel could not locate it in any reporter or database. When ordered to produce a copy of the decision, appellate counsel Jae S. Lee admitted she could not, and that the citation had come from ChatGPT.

The Second Circuit's January 30, 2024 opinion is notable for its restraint and its firmness at once: the panel did not impose a monetary sanction, but it held unambiguously that citing a nonexistent case falls below an attorney's basic professional obligations regardless of intent, and referred the matter to the court's Grievance Panel for further disciplinary review — a track record consequence, not just a one-time fine.

Bourguignon illustrates a pattern distinct from Mata v. Avianca: rather than six fabricated cases piled into one brief, this was a single invented citation in an otherwise ordinary reply brief, caught only because the panel tried to look it up before ruling. It is a reminder that a fabrication doesn't need scale to trigger discipline — one uncheckable name is enough. That a single-citation slip drew the same category of consequence — a formal disciplinary referral — as Mata's six-case pileup underscores that courts are increasingly treating any unverified AI citation as a serious professional-responsibility failure, not a forgivable one-off.