That approach may be a viable heuristic but it will only get you so far. It's like flagging an opinion because it doesn't rhyme with the opinions of others.

That's not what humans do when they are fact finding, though. It's not what a (proper) scientist would do if she/he discovered a great insight or theory and was wondering whether it was true.

If you're turning to LLMs for great insight or theory, you're definitely doing it wrong. These tools are for well trod terrain, and when they're really just making shit up, it's almost always different shit each time. So yes, it's a heuristic, but for dealing with the stochastic weirdness these models sometimes spit out it works pretty damn well.