Why is a therapist badly trained because something affected them? That's just a trait of being human and he did what many other humans do when that happens - he told someone (this is what therapists are supposed to do in this situation). Therapy training is not about teaching people to be emotionless. They are taught not to let it affect them to the point that it interfere with therapy. All we know is in the moment he felt uncomfortable and told someone. He made a simple statement that didn't signify anything more serious than awkwardness in the moment. Absolutely typical of all humans and no big deal. The thing that makes it a bigger deal is that he was being recorded so now the OP knows. This can happen if anybody's private conversation is taped, not just a therapist's. Who knows what people say about us in a private conversation? Most people, because of social norms (whether right or wrong), are not that transparent. It's likely he didn't say it in session because he didn't think it was important enough to tell her and risk making her self conscious. Again, That is normal human behavior.