What was hallucinated

False Quotes: Case Law | Quote attributed to STF RE 378.041; court found the phrase absent and no mention of Lei 8.437/92 in that judgment. || False Quotes: Case Law | Quote attributed to STJ REsp 1.200.000/SP; court found that case is a monocratic decision about justiça gratuita and does not contain the quoted passage; even the suggested RMS 35.905/MG lacks such foundation. || False Quotes: Case Law | Quote attributed to ADI 4.296/DF about 'inversão hierárqurica'; court found the ADI addressed Lei 12.016/09 and the quoted passage is not in the ruling.

Details

The court imposed a fine of 1 salário-mínimo for bad faith litigation and notified the OAB for potential professional sanctions.

Sanction teardown · São Paulo State Tribunal, Brazil · 2025-07-25

Silva Cordeiro v. Municipio de Santana do Parnaiba

What happened

In São Paulo State Tribunal, Brazil, 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:

False Quotes (Case Law)

Quote attributed to STF RE 378.041; court found the phrase absent and no mention of Lei 8.437/92 in that judgment.
False Quotes (Case Law)

Quote attributed to STJ REsp 1.200.000/SP; court found that case is a monocratic decision about justiça gratuita and does not contain the quoted passage; even the suggested RMS 35.905/MG lacks such foundation.
False Quotes (Case Law)

Quote attributed to ADI 4.296/DF about 'inversão hierárqurica'; court found the ADI addressed Lei 12.016/09 and the quoted passage is not in the ruling.

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 equivalent to one month of minimum wage (monetary penalty: 1 .)

Additional detail

The court imposed a fine of 1 salário-mínimo for bad faith litigation and notified the OAB for potential professional sanctions.

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.

Check a brief before you file it → · See our live false-verify rate

Source: https://www.damiencharlotin.com/documents/653/Silva_Cordeiro_v._Municipio_de_Santana_do_Parnaiba.pdf, via Damien Charlotin's public AI Hallucination Cases Database (CC0).