I don't think saying "this person" necessarily implies gender neutrality that the therapist should have picked up on. It can also be used as a way to avoid saying "my father" or "my uncle" or "my male teacher" etc. The therapist may very well have noticed the use of non-identifying information but perhaps chose not to address it immediately since this was the first time Precious Things offered details and she was having a very difficult time talking about it. I think it's unfair to assume that he should have noticed but didn't, or that he should have used the same non-identifying words Precious Things used, because without asking him why, we have no way to know what he was thinking or what his reason may have been for assigning a gender.