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In a footnote to its Riverside County ballot-seizure ruling, the California Supreme Court disapproved the improper use of AI tools that the court said apparently contributed to a misquoted precedent, and referred the matter to the State Bar to determine whether discipline is warranted
The case is about who may hold voted ballots. The AI point sits in footnote 7, where the court says AI tools apparently contributed to a misquoted precedent in the sheriff's briefing and sends the matter to the State Bar.
Bottom line: This is a filed opinion of the California Supreme Court in an original writ proceeding, dated September 24, 2026. Its holding concerns ballot custody. The AI passage is a footnote that disapproves improper AI use and refers the matter to the State Bar of California "to determine whether discipline is warranted". The referral is not a disciplinary finding and imposes no sanction.
Who this affects: California litigators and appellate counsel who file briefs in the state's courts, and the legal-ethics and risk managers at law firms who supervise how AI tools are used in drafting and cite-checking.
Issue date: Opinion filed September 24, 2026, No. S295866. The footnote sets no deadline, and the opinion says nothing about when or how the State Bar will act.
What changed: The court said the sheriff's preliminary standing challenge rested on "misquoted passages from, and an incorrect recitation of our holding in" Common Cause v. Board of Supervisors (1989). It disapproved the improper use of AI tools, which it said "apparently contributed" to the error, and referred the matter to the State Bar. That is a referral, not a disciplinary finding or a sanction.
Analysis: On our reading, the footnote attaches no new rule. It points counsel to existing duties of competence and candor under Rules of Professional Conduct 1.1 and 3.3. The firm apologized and withdrew the argument, and the court still made the referral.
Primary sources: Cervantes v. Bianco, No. S295866, Opinion (PDF, Supreme Court of California)
- Instrument (EN)
- Cervantes v. Bianco, Opinion of the Court, No. S295866, footnote 7
- Authority
- Supreme Court of California. Chief Justice Guerrero wrote the opinion; Justices Corrigan, Liu, Kruger, Groban, Evans and Burns concurred. Justice Liu also filed a concurring opinion
- Jurisdiction
- California (state court), original proceeding for a writ of mandate concerning ballots from Riverside County
- Status
- Decided. Petition for writ of mandate granted in part and denied in part. Footnote 7 refers the AI-related error to the State Bar of California
- Bindingness
- The writ binds the parties. The footnote's referral is a referral, not a finding of misconduct or a sanction
- Issue date / next deadline
- Filed September 24, 2026. No deadline is stated for the State Bar referral
- Rules cited in the footnote
- Rules of Professional Conduct, rules 1.1 and 3.3; canon 3D(2) of the California Code of Judicial Ethics
- Primary source
- https://www4.courts.ca.gov/opinions/documents/S295866.PDF
What did the court decide in the main case?
The court held that the Riverside County Sheriff's seizure of voted ballots was unlawful. Four Riverside County voters petitioned after the sheriff's department, acting on search warrants, seized approximately 650,000 ballots cast at the November 4, 2025 special election involving Proposition 50. The court found the seizure violated Elections Code section 15551, subdivision (d), and issued a peremptory writ directing Sheriff Chad Bianco to return all packages containing the voted ballots to the custody of the Registrar of Voters forthwith. Requests for the return of other election materials and a chain-of-custody report were denied without prejudice.
What does footnote 7 say?
The footnote is attached to the court's statement that "Bianco no longer contests petitioners' standing". In full, it reads:
"In his preliminary briefing, Bianco challenged petitioners' standing based on misquoted passages from, and an incorrect recitation of our holding in, Common Cause v. Board of Supervisors (1989) 49 Cal.3d 432 (Common Cause). The law firm responsible for the error apologized and withdrew Bianco's standing argument. We disapprove of the improper use of artificial intelligence tools, which apparently contributed to the significant error that occurred here and remind counsel of attorneys' professional duties of competence and candor to the court. (See Rules Prof. Conduct, rules 1.1, 3.3.) We also refer the matter to the State Bar of California to determine whether discipline is warranted. (See canon 3D(2) of the California Code of Judicial Ethics.)"
The footnote does not name the law firm, the lawyers involved or the AI tool. It does not describe how the error was discovered.
How far does the court's AI finding go?
The court's own word is "apparently". It says AI tools apparently contributed to the error, and it does not set out a finding on how the brief was drafted. The referral asks the State Bar to determine whether discipline is warranted. On the court's account, that question is open. No sanction was imposed in the opinion, and the court cites canon 3D(2) of the California Code of Judicial Ethics after the referral sentence, without further discussion.
The court records that the firm apologized and withdrew the standing argument, and it made the referral anyway.
What does this mean for California brief writers?
The footnote cites two existing Rules of Professional Conduct, rule 1.1 on competence and rule 3.3 on candor toward the tribunal. It does not announce an AI-specific rule or a disclosure requirement. In our reading, the practical point for appellate counsel and firm risk managers is narrower: a misquotation of controlling California Supreme Court authority, which the court said AI tools "apparently contributed" to, drew a referral from that same court even after an apology and withdrawal. The referral is not a disciplinary finding or a sanction; whether discipline is warranted is for the State Bar to determine.
Firms that review AI-assisted drafts may wish to check quotations against the reported opinion itself, since the error here was in the quoted language and in the description of the holding.
What we did not verify
What we opened: the full opinion PDF in No. S295866 from the California courts website, as text extracted from that PDF, including the majority opinion, footnote 7, the disposition, Justice Liu's concurrence and the counsel listing. Every quotation on this page comes from that file, with typographic quotes and apostrophes folded to straight ones and line breaks joined.
What we did not open: the sheriff's preliminary briefing, the firm's apology or withdrawal filing, the companion opinion in Bonta v. Bianco (S295901), any State Bar record, and the text of canon 3D(2). We did not check the docket for later filings.
What we refuse to claim: that any lawyer has been disciplined or sanctioned, that the court found AI use as a settled fact beyond its own word "apparently", or which firm or lawyer prepared the briefing. The counsel listing names more than one firm for the sheriff, and the footnote does not say which one was responsible. We make no claim about what the State Bar will decide.
Informational analysis for working professionals, not legal advice. Confirm how any rule applies to your situation with qualified counsel.
The California Supreme Court said improper use of AI tools apparently contributed to a misquoted precedent, and it referred the matter to the State Bar, even though the firm had apologized and withdrawn the argument. The referral is not a finding of misconduct. The duties it cites, competence and candor under rules 1.1 and 3.3, already apply. Checking each quotation and each description of a holding against the reported opinion goes to the kind of error the court described.
Source File
https://www4.courts.ca.gov/opinions/documents/S295866.PDF
Open the opinion in No. S295866 and confirm the filing date of September 24, 2026 on the cover page, the holding that the seizure was unlawful in the introduction, footnote 7 in Part II.B on standing, and the disposition in Part III granting the petition in part.
We disapprove of the improper use of artificial intelligence tools, which apparently contributed to the significant error that occurred here and remind counsel of attorneys' professional duties of competence and candor to the court. ยท Cervantes v. Bianco, Supreme Court of California, No. S295866, fn. 7, filed September 24, 2026
FAQ
Did the California Supreme Court sanction a lawyer for AI use?
No. The opinion imposes no sanction. It refers the matter to the State Bar of California "to determine whether discipline is warranted", which leaves that question to the State Bar.
What was the error?
The court said the sheriff's preliminary briefing challenged the petitioners' standing using misquoted passages from Common Cause v. Board of Supervisors (1989) 49 Cal.3d 432 and an incorrect recitation of its holding. The court said improper use of AI tools apparently contributed to that error.
Does the opinion name the law firm?
No. Footnote 7 refers only to "The law firm responsible for the error", which it says apologized and withdrew the standing argument. We do not identify the firm.
What was the case actually about?
Ballot custody. The court held that the Riverside County Sheriff's seizure of about 650,000 ballots from the November 4, 2025 special election was unlawful under Elections Code section 15551, subdivision (d), and ordered the ballots returned to the Registrar of Voters.
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