What was hallucinated

Fabricated: Case Law | Party said he wanted to cite "Liggett v. Lew Realty." LaSalle" || Misrepresented: Case Law || Misrepresented: Case Law | "Nothing in the Pusatere decision remotely addresses the issues raised in Respondent's motion to dismiss." || Misrepresented: Case Law || Misrepresented: Case Law | "The next twenty-five pages of the appendix contains the full text of the decision which does not in any way, shape, or form address [*9]whether the landlord-tenant relationship continues after the property is sold or anything else remotely connected to the issues raised in Respondent's motion to dismiss. Also concerning is that immediately following the full text of the Revis decision on page 58 is another instance of the following statement: "Some case metadata and case summaries were written with the help of AI, which can produce inaccuracies. You should read the full case before relying on it for legal research purposes."" || Fabricated: Case Law | Party said it should be Friedman v. Yosef, 2016 N.Y.Misc.LEXIS 384 (App. Term, 2nd Dept. 2016). || Misrepresented: Case Law || Fabricated: Case Law | Party said Vargas v. Sotelo, 2017 NY Slip Op 50417(U)(Civ. Ct., Bronx Cty. 2017) replaced the two fake cases || Fabricated: Case Law || Misrepresented: Case Law || Misrepresented: Legal Norm || Misrepresented: Case Law || Misrepresented: Legal Norm || Misrepresented: Case Law

Details

After being ordered to show cause, Counsel submitted a brief that compounded the issue."The Court was dismayed to see that some of the discussion/analysis provided by Mr. Chinweze appeared to be from artificial intelligence generated case summaries which was indicated by the inclusion several times of the statement that "Some case metadata and case summaries were written with the help of AI." Another indication that the paragraphs of discussion/analysis were copied from another source or were generated by AI is that several paragraphs have superscript for footnotes, but no footnotes are found on any page of the Appendix."The court then cited this database to highlight the growing problem of hallucinations in legal cases.Counsel was ordered to pay 1,000 USD to the Lawyers Fund for Client Protection, and he was referred to the bar authorities.

Sanction teardown · N.Y. Civil Court, USA · 2025-07-29

Happiness Idehen & Felix Ogieva v. Gloria Stoute-Phillip

What happened

In N.Y. Civil Court, USA, a filing relied on MS Copilot to help draft legal argument. The court identified the following problems with the citations in that filing:

Fabricated (Case Law)

Party said he wanted to cite "Liggett v. Lew Realty." LaSalle"
Issue

Misrepresented: Case Law
Misrepresented (Case Law)

"Nothing in the Pusatere decision remotely addresses the issues raised in Respondent's motion to dismiss."
Issue

Misrepresented: Case Law
Issue

Misrepresented: Case Law | "The next twenty-five pages of the appendix contains the full text of the decision which does not in any way, shape, or form address [*9]whether the landlord-tenant relationship continues after the property is sold or anything else remotely connected to the issues raised in Respondent's motion to dismiss. Also concerning is that immediately following the full text of the Revis decision on page 58 is another instance of the following statement: "Some case metadata and case summaries were written with the help of AI, which can produce inaccuracies. You should read the full case before relying on it for legal research purposes.""
Fabricated (Case Law)

Party said it should be Friedman v. Yosef, 2016 N.Y.Misc.LEXIS 384 (App. Term, 2nd Dept. 2016).
Issue

Misrepresented: Case Law
Fabricated (Case Law)

Party said Vargas v. Sotelo, 2017 NY Slip Op 50417(U)(Civ. Ct., Bronx Cty. 2017) replaced the two fake cases
Issue

Fabricated: Case Law
Issue

Misrepresented: Case Law
Issue

Misrepresented: Legal Norm
Issue

Misrepresented: Case Law
Issue

Misrepresented: Legal Norm
Issue

Misrepresented: Case Law

Which AI tool

MS Copilot. 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; referral to the Bar (monetary penalty: 1000 USD.)

Additional detail

After being ordered to show cause, Counsel submitted a brief that compounded the issue."The Court was dismayed to see that some of the discussion/analysis provided by Mr. Chinweze appeared to be from artificial intelligence generated case summaries which was indicated by the inclusion several times of the statement that "Some case metadata and case summaries were written with the help of AI." Another indication that the paragraphs of discussion/analysis were copied from another source or were generated by AI is that several paragraphs have superscript for footnotes, but no footnotes are found on any page of the Appendix."The court then cited this database to highlight the growing problem of hallucinations in legal cases.Counsel was ordered to pay 1,000 USD to the Lawyers Fund for Client Protection, and he was referred to the bar authorities.

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/645/Idehen_v_Stoute-Phillip_USA_29_July_2025.PDF, via Damien Charlotin's public AI Hallucination Cases Database (CC0).