Does This Case Really Exist?

I’m frequently asked to track down cases that lawyers can’t find. Most of the time the problem is an incorrect citation, but sometimes the problem is that the (usually older) case isn’t available in any online databases or print reporters. I’m now running into a new challenge: does the case exist or is it an AI hallucination?

I generally start with the assumption that the problem is an incorrect citation. In this situation, the most common issues are the misspelling of a party name or missing or incorrect numbers. I use multiple resources (e.g. CanLII, Lexis+, Westlaw Canada) and search for both style of cause and neutral citation. 

Determining something doesn’t exist can be tricky, especially if the citation is for an older case. I check for references to the case in other decisions or secondary sources; if I see multiple references to the case, then I know it exists. These references may also provide alternate citations or the dreaded “(unreported)”. If it’s a newer case, it may be that the court has chosen not to make it publicly available or that they have simply not made it available yet; for those cases I find LinkedIn can be helpful since people write posts about very recent cases.

If I’ve not been able to find the case or any reference to it, I check with the lawyer as to where they found the reference to the citation. If the response is that it was sent by a client, the chances that it is an AI hallucination greatly increases.

If I’ve established that the case was cited by a GenAI tool, especially one not designed for legal research, and there is no reference to the case anywhere else, it is safe to conclude it’s a hallucination; AI can’t find a case if there’s no reference to it on the internet. 

Another thing to keep in mind is that neutral citations only started being used in the very late 1990s. If the case uses a neutral citation but with a date that predates the use of neutral citations, that is another indication it is an AI hallucination.

— Susannah Tredwell