I'm wondering what anger looks like to you? Could you be seeing/hearing/feeling disappointment, frustration and taking it as anger? Maybe (most likely) I am wrong, but to me anger is a really intense emotion. When I'm angry I am unreasonable and not able to carry on a conversation with anyone. When I am frustrated or disappointed I am much more able to figure things out and talk through it.

My T gets frustrated with me at times. She doesn't always show it but I can feel it during the session.