What was hallucinated

Fabricated: Case Law | Brief at docket 39 contained citations to non-existent cases; the magistrate judge could not locate them and Rule 11 violation was admitted. || Fabricated: Case Law | Brief at docket 52 contained citations to non-existent cases; the magistrate judge could not locate them and Rule 11 violation was admitted. || Fabricated: Case Law | Brief at docket 65 contained citations to non-existent cases; the magistrate judge could not locate them and Rule 11 violation was admitted.

Details

(Earlier report and recommendation can be found here.)AI UseCounsel admitted at a show cause hearing that he used generative AI tools to draft multiple briefs and did not verify the citations provided by the AI, mistakenly trusting their apparent credibility without checking.Hallucination DetailsThree distinct fake cases across filings. Each was cited in a separate brief, with no attempt at Shepardizing or KeyCiting.Ruling/SanctionThe Court recommended a $15,000 sanction ($5,000 per violation), with the matter referred to the Chief Judge for potential additional professional discipline. Counsel was also ordered to notify Hoosiervac LLC’s CEO of the misconduct and file a certification of compliance.Eventually, the court fined Counsel $6,000, stressing that this was sufficient.Key Judicial ReasoningThe judge stressed that "It is one thing to use AI to assist with initial research, and even nonlegal AI programs may provide a helpful 30,000-foot view. It is an entirely different thing, however, to rely on the output of a generative AI program without verifying the current treatment or validity—or, indeed, the very existence—of the case presented. Confirming a case is good law is a basic, routine matter and something to be expected from a practicing attorney. As noted in the case of an expert witness, an individual's "citation to fake, AI-generated sources . . . shatters his credibility." See Kohls v. Ellison, No. 0:24-cv-03754-LMP-DLM, Doc. 46 at *10 (D. Minn. Jan. 10, 2025)."

Sanction teardown · S.D. Indiana, USA · 2025-05-28

Mid Cent. Operating Eng'rs Health v. Hoosiervac

What happened

In S.D. Indiana, USA, a filing relied on an unnamed/unconfirmed AI tool to help draft legal argument. The court identified the following problems with the citations in that filing:

Fabricated (Case Law)

Brief at docket 39 contained citations to non-existent cases; the magistrate judge could not locate them and Rule 11 violation was admitted.
Fabricated (Case Law)

Brief at docket 52 contained citations to non-existent cases; the magistrate judge could not locate them and Rule 11 violation was admitted.
Fabricated (Case Law)

Brief at docket 65 contained citations to non-existent cases; the magistrate judge could not locate them and Rule 11 violation was admitted.

Which AI tool

an unnamed/unconfirmed AI tool. Note: Charlotin's public database records tool attribution only where a court order, brief, or reporting on the matter states it explicitly; "unidentified" or "implied" means the record indicates AI use but does not name a specific product — we do not guess.

Outcome

Monetary Sanction (monetary penalty: 6000 USD.)

Additional detail

(Earlier report and recommendation can be found here.)AI UseCounsel admitted at a show cause hearing that he used generative AI tools to draft multiple briefs and did not verify the citations provided by the AI, mistakenly trusting their apparent credibility without checking.Hallucination DetailsThree distinct fake cases across filings. Each was cited in a separate brief, with no attempt at Shepardizing or KeyCiting.Ruling/SanctionThe Court recommended a $15,000 sanction ($5,000 per violation), with the matter referred to the Chief Judge for potential additional professional discipline. Counsel was also ordered to notify Hoosiervac LLC’s CEO of the misconduct and file a certification of compliance.Eventually, the court fined Counsel $6,000, stressing that this was sufficient.Key Judicial ReasoningThe judge stressed that "It is one thing to use AI to assist with initial research, and even nonlegal AI programs may provide a helpful 30,000-foot view. It is an entirely different thing, however, to rely on the output of a generative AI program without verifying the current treatment or validity—or, indeed, the very existence—of the case presented. Confirming a case is good law is a basic, routine matter and something to be expected from a practicing attorney. As noted in the case of an expert witness, an individual's "citation to fake, AI-generated sources . . . shatters his credibility." See Kohls v. Ellison, No. 0:24-cv-03754-LMP-DLM, Doc. 46 at *10 (D. Minn. Jan. 10, 2025)."

How Citation Safe would have caught this

Citation Safe runs three deterministic layers before a brief is filed: (1) does the citation exist against CourtListener's database of published opinions, (2) if quoted, does that exact language appear in the source, (3) does the cited case actually support the proposition it is cited for. Fabricated case citations fail Layer 1. Fabricated or misattributed quotations fail Layer 2 even when the underlying case is real. Misrepresented holdings — a real case cited for a proposition it does not support — are the target of Layer 3. None of these checks involve asking another language model whether the citation looks right; they are lookups and text-matches against the actual source, which is why a hallucinated citation has to survive a direct lookup against the authoritative source — not another model's opinion — to earn a VERIFIED stamp; our measured false-verify rate is published live at /quality.

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Source: https://www.damiencharlotin.com/documents/453/Mid_Cent._Operating_Engrs_Health_v._Hoosiervac_S.D._Indiana_USA_May_28_2025.pdf, via Damien Charlotin's public AI Hallucination Cases Database (CC0).