County of Los Angeles v. Niblett
California Court of Appeal, Second District, Division One · Cal. Ct. App. · California bar guidance
Verified September 30, 2026
- Citation
- County of Los Angeles v. Niblett, No. B327744, 2025 WL 3060520 (Cal. Ct. App. Oct. 31, 2025) (unpublished)
- Decided
- October 31, 2025
Summary
Appellate counsel Robert W. Lucas, representing appellant Neill Francis Niblett, filed an opening brief that cited a fabricated case (Montebello Unified School District v. State Board of Education (1991) 226 Cal.App.3d 1685) and misrepresented the holdings of several real authorities, including United States v. Rahimi, Scripps Health v. Marin, Bookout v. Nielsen, and a nonexistent "R.D. v. P.M. (2021) 68 Cal.App.5th 1012." After the County identified the errors, Lucas filed a notice of errata conceding the Montebello citation "does not appear to exist" and stating it "was added by the artificial intelligence editing which [he] did not catch before filing." The panel (Bendix, Acting P.J., joined by Weingart, J., and M. Kim, J.) found Lucas failed to correct most of the miscitations even after the County flagged them.
- AI tool:
- Unspecified generative AI
- Sanction amount:
- $5,000 against attorney Robert W. Lucas individually, payable to the clerk of the Second District within 30 days after remittitur; opinion and order sent to the State Bar under Bus. & Prof. Code § 6086.7(a)(3)
What sanction did the court impose?
The Court of Appeal affirmed the underlying workplace violence restraining order and, in a separate ruling issued concurrently with the opinion, ordered Attorney Lucas to show cause why sanctions should not be imposed for misuse of artificial intelligence in briefing the appeal. On November 25, 2025 the court filed an order imposing sanctions: "we order Robert W. Lucas individually to pay $5,000 to the clerk of the Second District no later than 30 days after the remittitur is filed," and directed the clerk to send the opinion and the order to the State Bar under Business and Professions Code section 6086.7(a)(3). The remittitur issued on February 25, 2026, and the docket records the letter to the State Bar on March 6, 2026 and Lucas's sanctions check on March 10, 2026.
Why does County of Los Angeles v. Niblett matter for law firms using AI?
Niblett illustrates that the AI hallucination problem has reached intermediate appellate practice in California, and that “I did not knowingly use AI” is no longer a defense once a brief contains a fabricated citation. The court treated counsel’s failure to correct flagged miscitations after the respondent’s brief identified them as the more troubling conduct, signaling that the duty to verify continues after filing. For managing partners, the case underscores that appellate-level review now routinely includes a citation audit, and that an unchecked AI editing pass on an opening brief can produce a published show-cause order naming counsel by name.
Sources
Primary sources
Further reading
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.