As opposed to manually trawling through thousands of documents, based on a keyword that may, or may not, appear in the context of the case file?

It's a huge boon, but nothing is perfect. If it's that important that absolutely nothing is missed, maybe try multiple approaches concurrently. Take this as a value add, not a replacement.

If you don't already grok all the legal jargon, the LLM is probably better than a keyword search.

I'm not a lawyer, so when I search British copyright law, I wonder why those forms of words don't result in the staff of search engines and social media sites being arrested and imprisoned:

https://www.gov.uk/government/publications/intellectual-prop...

Although, probably best to ask a lawyer for legal advice even if they end up using GPT-n themselves; they've probably got public liability insurance if they get something wrong.

Humans miss things all the time. It's okay to make mistakes.