Ng v. AmGuard Insurance Company
U.S. District Court, Southern District of New York · S.D.N.Y. · New York bar guidance
Conduct
Pro se plaintiff cited a fabricated First Department case in an insurance dispute; court flagged AI-style hallucination.
Consequence
Warning from S.D.N.Y. Magistrate Judge Stein; no monetary sanction or referral.
Lesson
Single-citation hallucinations get warnings in S.D.N.Y., consistent with the broader pro se warning-first pattern.
Verified May 7, 2026
- Citation
- Ng v. AmGuard Ins. Co., S.D.N.Y. (Stein, M.J.) (Dec. 29, 2025)
- Decided
- December 29, 2025
Summary
Pro se plaintiff Ng filed papers in a first-party insurance dispute against AmGuard Insurance Company that cited "Greyhound-Thermalink, Inc. v. B.U.R. Realty Corp., 42 A.D.3d 319, 320 (N.Y. 1st Dep't 2007)," a citation the court's research found does not exist. Magistrate Judge Gary Stein issued a warning to the plaintiff about AI-generated fake citations.
- AI tool:
- Implied (court suspected AI hallucination; specific tool not identified)
What sanction did the court impose?
Warning issued by Magistrate Judge Stein; no monetary sanction or disciplinary referral imposed.
Why does Ng v. AmGuard Insurance Company matter for law firms using AI?
Ng v. AmGuard is a small but operationally useful precedent for first-party insurance defense practice in S.D.N.Y. The hallucination here is a single fabricated First Department citation (Greyhound-Thermalink), and the disposition is a warning rather than sanctions, consistent with the broader S.D.N.Y. pro se pattern. The substantive lesson for firms is that even single-citation AI fabrications are now grounds for a court-issued warning, which becomes part of the docket record and may inform a more severe response on the next occurrence by the same litigant.
For carriers and their counsel facing pro se policyholders in S.D.N.Y., the operational implication is that verifying every cited New York appellate case before writing the response brief is now table stakes. The Ng case is particularly notable because the plaintiff has filed serially against AmGuard (multiple S.D.N.Y. dockets); accumulated AI-hallucination warnings across related dockets may support a stronger sanctions request on a future filing.
Implications for your firm
Operational steps a firm reading this case may wish to consider documenting. Strategic and rule-application calls belong to your firm's attorneys.
- First-party insurance defense in S.D.N.Y. against pro se policyholders is a recurring AI-hallucination context; verify cited New York Appellate Division authority before responding.
- Pro se serial filers (Ng has multiple S.D.N.Y. dockets against AmGuard) accumulate warnings across cases; track prior AI-hallucination warnings as part of the litigation history when responding to a new filing from the same party.
Sources
Primary sources
Further reading
- R&G's tracker lists two separate Ng v. Amguard entries: 'Brian NG' (2025-12-29) and 'Matthew NG' (2025-12-12), both before Magistrate Judge Stein. Charlotin's database lists only one entry, captioned 'Ng v. AmGuard Insurance Company,' dated 2025-12-29. CourtListener shows multiple Ng v. Amguard dockets in S.D.N.Y. (1:25-cv-00806 filed 2025-01-28, 1:25-cv-07855 filed 2025-09-22, 1:26-cv-02432 filed 2026-03-25), suggesting the same plaintiff has filed serially. R&G's 'Brian' and 'Matthew' first names are not corroborated by Charlotin or by any docket caption visible on CourtListener; the canonical caption is simply 'Ng.' Treated as a single case here.
- Specific S.D.N.Y. docket number for the December 29, 2025 order is not confirmed; multiple Ng v. AmGuard dockets exist. The 1:25-cv-00806 docket (filed January 2025) is the most likely match for a December 29, 2025 order.
- Order text was not extracted verbatim during this verification pass; Charlotin's CSV synopsis is the source for the substantive narrative.