Interesting idea. That would be a nice wrinkle if she's been lying but comes off as so sincere that it avoids 'the glow' (must be a Japanese cultural idiom) that manager-kun picks up on.

I also meant to mention I like that his seeing lies (that often) hasn't made him into a cynical jerk who expects the worst from people, as is common in anime. He has the maturity to know that sometimes people want to avoid telling the truth because, in their judgement, the cons outweigh the pros. I'm just glad he doesn't flaunt people's dishonesty in their faces and act superior because he has a sort-of super power.