Several months ago, my therapist said something to me that stung (on a different topic than yours). I didn't say or do anything, but she saw right away that it had an effect on me. She outright said that she could see she had hurt my feelings and was sorry. I said yeah, it did hurt. That was about the extent of it, though. There wasn't much more for either of us to say on it. She had chosen her words poorly, but what she'd said wasn't untrue, so it wasn't like I could argue about it. There was an earlier thing that had happened that hurt, too, but was also unavoidable, and she did what she could to correct it. We talked about that again today and she understood from a deeper level why that thing that happened had hit directly on my soft spot. It worked out pretty well because it brought out something I don't deal with, but need to.

Basically, I don't think that being hurt is avoidable, but it can be helpful if a) the therapist apologizes and b) the deeper issue is addressed. In your case, I would bring it up at some point to make sure your relationship is okay and that he understands how that was hurtful.