Do you think that is that a hint?
A hint of what?
Do you think the GP is not looking for a PD? Or is it Waaayyyyyyy too early to tell? Do you think a psychologist would be able to dx? Or would it take a psychiatrist?
Hmm. In the US, I believe that only a psychologist or a psychiatrist can
diagnose mental disorders. And I believe it would be normal for a GP to refer the patient to one, for anything beyond maybe a careful trial of an antidepressant for mild depression.
That said, you don't actually know that there is a PD - only a qualified mental health professional can diagnose one. And differential diagnosis can
be difficult - there are a lot of similarities between bipolar and BPD, and PTSD and BPD.
To put it simply, you don't actually know
that he suffers from BPD.
Given the opportunity, you could certainly encourage him to get evaluated by a clinical psychologist or a psychiatrist. That's likely to be helpful no matter what he suffers from.