I think it's more than fair to have an expectation of closer attention when actual trauma is being discussed. I had one therapist fall asleep when I finally took the step of revealing to him some of the most painful aspects of my experience with CSA. Made it very difficult to entrust him with tender details again, especially since he never explained himself, just looked at me when he came out of his nap a few minutes later as if it was my fault somehow. Maybe it was. Maybe hearing about my trauma experience inherently had the potential to knock him out cold, but if so I don't know why he asked me the questions. In my defense, I was so embarrassed that my horrific trauma story so bored him as to lull him into a nap I didn't know what to do. I was afraid to startle him by speaking loudly or tapping him on the knee. If he suffered from narcolepsy, that would have been a good time for him to mention it. But nary a word was offered, only an annoyed glare at me and never spoken of again. Awkward. Unfortunately, after that I feared that a retelling of my experience could put the man into a coma. Maybe it was I that was retraumatizing him. But, I digress somewhat.

It's been frustrating to me how resistant therapists can be to the very suggestions which in consideration could help them to evolve in their role and process, but I certainly wouldn't let him weasel out of it by relating it to your issues. If he claims to have not been inattentive, let him quantify what attentive looks like for him and how you will be able to note it in future, so that topics about which you are particularly tender do not result in further emotional trauma for you. Telling you that you're imagining it or that it's all about your issues is not particularly constructive for the future of a therapy relationship. I know therapists like to think of themselves as becoming a blank slate for us but the fact is there are 2 people in the room, and both are involved in what happens for the relationship.