What do I do if ChatGPT invented a case citation I already filed?

Stop treating the citation as authority. Inventory every citation and proposition that came from a generative tool or that nobody can verify in a reporter or on the docket. Tell supervising counsel the same day. Correct the tribunal under that court's rules. Tell the client if the error is material. Keep the prompts, drafts, and review notes. Then harden the firm AI policy so the next filing does not leave without a signed verification step.

California attorney: AI hallucinated citation already filed

Q: Does ABA Formal Opinion 512 require correcting a false citation already filed?

Opinion 512 maps generative-AI use onto existing Model Rules. Under Rule 3.3, a lawyer may not knowingly make a false statement of law or fact to a tribunal and must correct a material false statement the lawyer previously made. Uncritical reliance on generated output can also implicate competence and supervision duties.

This is the incident question after a filing left the office. Courts respond better to a prompt correction than to a fabrication found by the other side. This page is not legal advice.

In Mata v. Avianca, Inc., No. 22-cv-1461 (PKC) (S.D.N.Y.), Judge P. Kevin Castel issued an Opinion and Order on Sanctions on June 22, 2023. The public record describes Rule 11 sanctions (or alternatively the court's inherent authority): a monetary penalty and letters disclosing the false citations. The useful lesson for any jurisdiction, including California practice, is not that a tool is banned. A filing left the office without a documented verification step. The lawyers remained responsible for what was submitted.

A shorter national checklist lives here: What to do if a hallucinated citation already reached a filing. This page adds the California overlay California attorneys ask for when the search is crisis-shaped.

What ABA Formal Opinion 512 and California guidance add

ABA Formal Opinion 512 (July 29, 2024) maps generative-AI use onto existing Model Rules. Under Rule 3.3, a lawyer may not knowingly make a false statement of law or fact to a tribunal, and must correct a material false statement the lawyer previously made. Uncritical reliance on generated output can implicate Rule 1.1. Rules 5.1 and 5.3 put supervisory duty on the lawyers who manage the firm.

The California State Bar Practical Guidance on the Use of Generative Artificial Intelligence in the Practice of Law (November 2023) is the California-specific reading California attorneys should keep next to Opinion 512. It does not replace a tribunal's local rules on how to correct a filed paper.

If the citation you cannot verify is already in a filing

Stop using it as authority. Do not quote it again in a letter, a reply, a meet-and-confer, or an oral argument.
Inventory the damage. List every citation, quote, and legal proposition that came from a generative tool, or that nobody can point to in a reporter, on CourtListener, or on the docket.
Tell supervising counsel the same day. Rules 5.1 and 5.3 are about the firm, not only the associate who pressed send.
Correct the tribunal. How you correct it depends on that court's rules. Many courts respond better to a voluntary notice of errata or a letter that withdraws the fabricated authority and explains the miss than to silence. A lawyer admitted in the matter has to make that call.
Do not cover it up. Hiding the error after you know the citation is false is a separate candor problem from the original miss.
Tell the client if the error is material to the representation. What counts as material is a judgment for counsel on that matter. Rule 1.4 is the communication frame Opinion 512 points back to.
Keep the record. Do not delete the prompts, the draft, the tool output, or the review notes. Sanctions opinions turn on what the lawyers knew and when.
Write the miss into the firm AI policy. Who may use which tool, what may never be pasted into a consumer chatbot, and which citations require a signed check before the next filing leaves the office. See what a law firm AI use policy should include.

What courts have rewarded in the public record

Public write-ups of the Mata sanctions and later fabricated-citation orders repeatedly emphasize the same pattern: prompt voluntary correction, a plain explanation, and concrete remedial steps inside the firm beat defensive rationalizations. That pattern is a reading of public orders. It is not a promise that any particular California court will treat a given filing the same way.

After the filing is corrected

Train the people who draft and the people who supervise — a prohibition email is not a training step.
Put vendor questions in writing before the next pilot has client files in it. See questions to ask an AI vendor before a law firm signs.
Treat verification as a filing gate, not a personal preference.

The on-demand California MCLE course is $249. It includes the five modules, the 111-page reading, and the 35-question assessment. California MCLE accreditation is pending. The certificate is issued when the provider number is assigned. The course does not guarantee compliance, prevent sanctions, or satisfy a court, insurer, or client.

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