So you've come up with a heuristic that says 1) doing your own research is fine, and 2) people who tell you to do 1) are suspect?

If so, I can't imagine thats very effective. You're probably better off just assuming strangers don't know what they're talking about unless you have some good reason to believe otherwise.

No, I think that people who treat "Do your research!" as an argument are peddling suspect information.

If they had good information, they'd have good sources.