I would add that "hallucinations" aren't even the only failure mode a LLM can have, it can partially or completely miss what its supposed to find in the discovery process and lead you to believe that there just isn't anything worth pursuing in that particular venue.

> it can partially or completely miss what its supposed to find in the discovery process and lead you to believe that there just isn't anything worth pursuing in that particular venue.

The problem is that American and UK legal systems never got forced to prune the sometimes centuries-old garbage. And modern Western legal systems tend to have more explicit laws and regulations instead of prior case law, but still, they also accumulate lots of garbage.

IMHO, all laws and regulations should come with a set expiry date. If the law or regulation is not renewed, it gets dropped off the book. And for legal systems that have case law, court rulings should expire no later than five years, to force a transition to a system where the law-passing body is forced to work for its money.