It's not really a stupid move if he didn't know anything beforehand. The dark/evil smoke puffed out AFTER he talked about his friend, so how would he know it would be a bad idea otherwise?
True, and I forgot that as a reader we have the full story and him not…but the guy was still a bit off…and except for the dark smoke, I assumed, maybe wrongly, that being an abused child made him more sensible or receptive to feeling or like when you have bad hunch about someone…
He may be off to us readers, but as you said, we have the full story and fiction is bound to HAVE something wrong/someone bad for the "conflict" so we can have "conflict resolution". Also, I don't think he's the type of person who'd easily judge a person. I think MC is more of the "give them the benefit of the doubt" kind of person even if he DID, maybe, feel a person is off. But of course, seeing that smoke, he knows now probably?
Oh shoot he kinda fucked up…..
Spoiler:
From what I understood, because he mentioned the name of his girl friend to the bad guy, she will suffer because the main actress is working under the bad guy and will bully her…..kind of a stupid move on the part of the mc…