Pennantia, LLC v. Rose Cay Maritime, LLC
U.S. District Court, Southern District of New York · S.D.N.Y. · New York bar guidance
Verified October 1, 2026
- Citation
- Pennantia, LLC v. Rose Cay Maritime, LLC, No. 25-cv-5904 (SHS), Order (S.D.N.Y. Sept. 26, 2025) (ECF No. 70); see also Order (S.D.N.Y. Aug. 26, 2025) (ECF No. 56)
- Decided
- September 26, 2025
Summary
Counsel for defendant Dove Cay, LLC submitted an opposition to plaintiff Pennantia's motion for a preliminary injunction (ECF No. 32) that included two parenthetical quotations attributed to Crescent Towing & Salvage Co. v. M/V ANAX, 40 F.3d 741 (5th Cir. 1994), and General Electric Credit Corp. v. Drill Ship Mission Exploration, 668 F.2d 811 (5th Cir. 1982). Judge Sidney H. Stein read both decisions and confirmed neither contained the quoted language, nor could the language be located in any other federal or state court decision. The court further found the cited cases did not support the propositions for which they were offered.
- AI tool:
- Unspecified generative AI
How did the court address the AI-related conduct?
No sanction was imposed. Judge Stein first directed Dove Cay to file a letter by August 29, 2025 explaining how the apparently nonexistent quotations ended up in its memorandum (ECF No. 56). On September 4, 2025 the court ordered counsel to show cause why sanctions should not be imposed on Lennon Murphy & Phillips LLC under Rule 11 or its inherent power (ECF No. 62). On September 26, 2025, citing counsel's acknowledgment that the quotations were not independently verified, its acceptance of responsibility and its remedial measures, the court said it "will take no further action on this matter at this time" (ECF No. 70). The orders do not name a specific AI tool.
Why does Pennantia, LLC v. Rose Cay Maritime, LLC matter for law firms using AI?
Pennantia is an unusually clean illustration of the false-quote variant of AI hallucination: real cases, correctly cited by reporter and pin-cite, but with parenthetical quotations that do not appear anywhere in the cited opinions or in any other reported decision. The trial judge caught it by reading the cited cases. For a managing partner, the operational lesson is that citation verification cannot stop at confirming the case exists; any quoted language pulled from a generative tool must be checked against the source text before filing.
Sources
Primary sources
- CourtListener docket (primary source)
- CourtListener docket (primary source)
- CourtListener docket (primary source)
Further reading
- Document mirror (Damien Charlotin hallucination database, Westlaw printout)
- Justia (legal aggregator)
Source PDF is a Westlaw printout mirrored from the Damien Charlotin hallucination database. We are working to add the underlying court docket (PACER, CourtListener, or court website) as a second source.