That is correct, however the doctor is a hair loss specialist (and also has alopecia himself, which I feel may mean he is quite familiar with the condition).
Agree that he can weigh in on whether the scar is not alopecia, but less so on whether it is a scar (or from what). Also, he's not saying that the balding is from a scar, which was the impression I got when I first read your comment.
