What was hallucinated

Fabricated: Case Law | Petitioner cited RE 328.111/DF as precedent allegedly violated; the Court stated it could not locate such decision. || Fabricated: Case Law | Petitioner cited ARE 1.218.084 AgR as precedent allegedly violated; the Court stated it could not locate such decision. || Fabricated: Case Law | Petitioner cited RE 464.867/SP as precedent allegedly violated; the Court stated it could not locate such decision. || False Quotes: Legal Norm | Petitioner attributed to SV 6 a rule on penal acquittal barring administrative sanction; the Court said SV 6 actually concerns pay for initial military service. || Misrepresented: Case Law | Petitioner invoked RE 226.855/RS as supporting penal absolution’s binding effects; the Court clarified the case addressed FGTS monetary correction from economic plans, unrelated to the issue.

Details

AI UseThe petition’s pages were marked “Criado com MobiOffice.” The STF verified that MobiOffice includes a built-in AI writing assistant. Combined with the inclusion of fictitious citations, this led the Court to conclude that AI had been used and not reviewed. The judge characterized this as reckless conduct.Hallucination DetailsClaimed violations of STF precedents including RE 464.867/SP and RE 226.855/RS, which were either inapplicable or misrepresentedClaimed Súmula Vinculante 6 said something entirely false (its actual content concerns military service remuneration)Cited judgments ARE 1.218.084 AgR and RE 328.111/DF as relevant when they were either misquoted or irrelevantCourt concluded these references were invented or misrepresented, “false statements intended to mislead”Ruling/SanctionRejected the complaint as manifestly inadmissibleFound that counsel likely used AI and submitted the petition without reviewOrdered notification to both the national and Bahia sections of the OABDeclared the petitioner litigated in bad faith under Article 80, V, of the Brazilian Civil Procedure CodeImposed a procedural penalty of double the initial court costsOrdered referral to dívida ativa (federal collections) if not paid.

Sanction teardown · Supremo Tribunal Federal, Brazil · 2025-05-12

Jamisson Roriz de Santana Andrade v. Tribunal Superior do Trabalho

What happened

In Supremo Tribunal Federal, Brazil, a filing relied on Implied use of MobiOffice's AI Assistant to help draft legal argument. The court identified the following problems with the citations in that filing:

Fabricated (Case Law)

Petitioner cited RE 328.111/DF as precedent allegedly violated; the Court stated it could not locate such decision.
Fabricated (Case Law)

Petitioner cited ARE 1.218.084 AgR as precedent allegedly violated; the Court stated it could not locate such decision.
Fabricated (Case Law)

Petitioner cited RE 464.867/SP as precedent allegedly violated; the Court stated it could not locate such decision.
False Quotes (Legal Norm)

Petitioner attributed to SV 6 a rule on penal acquittal barring administrative sanction; the Court said SV 6 actually concerns pay for initial military service.
Misrepresented (Case Law)

Petitioner invoked RE 226.855/RS as supporting penal absolution’s binding effects; the Court clarified the case addressed FGTS monetary correction from economic plans, unrelated to the issue.

Which AI tool

Implied use of MobiOffice's AI Assistant. 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

Case summarily dismissed; Counsel referred to the Bar Association; Claimant ordered to pay double the costs

Additional detail

AI UseThe petition’s pages were marked “Criado com MobiOffice.” The STF verified that MobiOffice includes a built-in AI writing assistant. Combined with the inclusion of fictitious citations, this led the Court to conclude that AI had been used and not reviewed. The judge characterized this as reckless conduct.Hallucination DetailsClaimed violations of STF precedents including RE 464.867/SP and RE 226.855/RS, which were either inapplicable or misrepresentedClaimed Súmula Vinculante 6 said something entirely false (its actual content concerns military service remuneration)Cited judgments ARE 1.218.084 AgR and RE 328.111/DF as relevant when they were either misquoted or irrelevantCourt concluded these references were invented or misrepresented, “false statements intended to mislead”Ruling/SanctionRejected the complaint as manifestly inadmissibleFound that counsel likely used AI and submitted the petition without reviewOrdered notification to both the national and Bahia sections of the OABDeclared the petitioner litigated in bad faith under Article 80, V, of the Brazilian Civil Procedure CodeImposed a procedural penalty of double the initial court costsOrdered referral to dívida ativa (federal collections) if not paid.

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/334/Santana_Andrade_v._TST_Brazil_May_12_2025.pdf, via Damien Charlotin's public AI Hallucination Cases Database (CC0).