For me, when I read someone's post saying "it sounds like this" or "it could be that" or "I'm not a doctor, but maybe it's...", when I read comments phrased that way, I personally don't see it as diagnosing, no, I see it as someone just offering a layman's opinion and perhaps an avenue to explore - not a diagnosis saying, "Yes, you have such and such disorder for sure. Good luck!" So, it's the way the person is phrasing it that makes the difference between an apparent diagnosis and just offering an avenue to explore or an opinion about something. Saying "sounds like" or "perhaps you could look into this disorder" is a different thing. To me.

So, that's another aspect to this whole question.