What was hallucinated

Fabricated: Case Law | Defendant's written submissions relied on 11 non-existent cases to argue courts require convincing circumstantial evidence in civil trespass. || Misrepresented: Case Law | Halliday v Nevill was cited to support a civil trespass rule about circumstantial evidence, but the case concerns implied licence for police entry, not circumstantial evidence standards. || Misrepresented: Case Law | R v Baden-Clay was cited for circumstantial evidence in civil trespass; the case addresses the criminal standard of proof beyond reasonable doubt in a murder prosecution.

Details

"Generative AI can be beguiling, particularly when the task of representing yourself seems overwhelming. However, a litigant runs the risk that their case will be damaged, rather than helped, if they choose to use AI without taking the time to understand what it produces, and to confirm that it is both legally and factually accurate. "

Sanction teardown · Melbourne County Court, Australia · 2025-06-27

Page v. Long

What happened

In Melbourne County Court, Australia, 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)

Defendant's written submissions relied on 11 non-existent cases to argue courts require convincing circumstantial evidence in civil trespass.
Misrepresented (Case Law)

Halliday v Nevill was cited to support a civil trespass rule about circumstantial evidence, but the case concerns implied licence for police entry, not circumstantial evidence standards.
Misrepresented (Case Law)

R v Baden-Clay was cited for circumstantial evidence in civil trespass; the case addresses the criminal standard of proof beyond reasonable doubt in a murder prosecution.

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

Litigant lost on merits

Additional detail

"Generative AI can be beguiling, particularly when the task of representing yourself seems overwhelming. However, a litigant runs the risk that their case will be damaged, rather than helped, if they choose to use AI without taking the time to understand what it produces, and to confirm that it is both legally and factually accurate. "

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/532/Page_v._Long_27_June_2025_Australia.docx, via Damien Charlotin's public AI Hallucination Cases Database (CC0).