A screen producing a case citation has never been proof the case exists.
Short answer
There’s no blanket Canadian rule against material that AI helped produce. But admissibility and reliability are different hurdles, and current court guidance treats AI output exactly the way it treats any unverified, unsourced document — not automatically accepted, and not automatically excluded either, just because a machine produced it.
Ontario’s Consolidated Civil Practice Direction is explicit about the failure mode: “the court will not tolerate inadvertence”, and warns that this “most often… occurs when counsel or litigants carelessly rely on fictitious authorities generated by AI, commonly referred to as ‘hallucinations’. Hallucinations can consist of non-existent cases, mischaracterizations of case law, and fabricated quotations.” The problem the court is guarding against is a fabricated authority, not the fact that a tool was involved in drafting.
The same Practice Direction builds in a structural check: an authority published on a government website, on CanLII, on a court’s own site or by a commercial publisher “is presumed to be authentic… absent evidence to the contrary”, and every factum must carry a lawyer’s certification of that authenticity under Rule 06.1. An AI-suggested citation that can’t be found on any of those sources fails this test immediately — which is exactly the point.
That authentication requirement isn’t only a court practice direction — it has a statutory root. Canada Evidence Act s.31.1 puts the burden squarely on whoever wants the document admitted: “any person seeking to admit an electronic document as evidence has the burden of proving its authenticity by evidence capable of supporting a finding that the electronic document is that which it is purported to be”.
Text messages and emails have needed authentication in an Ontario civil case long before generative AI existed — a question with its own existing answer. AI-produced material is judged by the same underlying evidentiary standard: a document or record is only as good as what can be shown about where it came from and whether it is accurate, and that test doesn’t change based on which tool typed the first draft.
A citation to a case, statute or quotation that does not exist — not the underlying idea that AI touched the document. See can I use AI to write a court document for the drafting rules this failure sits behind.
Verifying that a claim or a document holds up before relying on it is the same discipline a diligence review runs on anything AI touched.
