In my case my T said he sounds like a murderous man or he acted in a psychopathic way. so for me alone it was, but it wasn't a diagnosis. But I understand what you're saying, feelings are always valid and using diagnostic terminology for someone they haven't met might seem wrong, but I think that depends on the situation and the person. It was what I needed to hear because I suspected my SD was a psychopath. Coming from someone who is trained in mental health really solidified this for me in a way I never thought was possible.

I think it all comes down to if your T is confident on saying it given the information they have, as well as taking your word as truth. I've only realised recently how much I needed my T's validation, but more recognition of my suffering because no one ever had. People watched me suffer and said nothing, so in a sense I really needed someone to hear me and I feel like she did. It was the right thing for me, and she sensed that, but it might not be right for everyone. In terms of the question I think it was meant the way my T said it. Not definitively, but saying a person sounds like they have tendancies, or symptoms of a particular mental illness they are aware of.