I personally rely on this behavior of LLMs. For example, for reviewing prose, I might ask the LLM to find five issues. If there are obvious issues I missed, then it'll find them. But if all the issues it lists are minor or hallucinated, then I can have some confidence there weren't any glaring issues.

I do the same for LLM code review comments: some changes are out of scope or could be moved to a separate PR; some edge cases don't happen in practice and should just fail noisily instead of writing more code to maintain. When these are the only issues it's raising, then I know it's done.