I wonder this a lot. I'm usually pretty honest about how my T has hurt me with her words or actions, and she does apologize. She's told me that she's lost sleep thinking about our conversations and wondering how she could have said something in a better way.
But... one of my (unrealistic) problems with her is that I don't affect her in the way I want to. She can turn thoughts of me off whenever she wants -- she has a family and is very wealthy and has all these other things that I want, and it just destroys me that she's always off having a great time while I'm alone and not able to get her off my mind in the same way.