I wonder if your therapist's comment about her boundary responsibilities wasn't so much a denial of your right to set boundaries in the relationship so much as asserting that it's the therapist's duty to ensure yours are not violated--in other words, another way of acknowledging that the fault of what happened with previous abuser therapist lies with him, not you. If she were to say the responsibility of boundaries in your relationship is all on you, then that could lead to self-blame when a therapist does wrong. Not sure if that makes sense. I guess I see it as a supportive statement.