I remember one of my therapists once said something that came out very badly. It wasn't what he meant to say, but it come out anyway and I had an immediate visceral reaction and started dissociating badly. He knew right away what had happened and worked to get me through that reaction, and he apologized profusely afterwards for his careless words.

We talked about what had happened and how it had affected me. I was able to get past it because I knew he had just badly misspoken; he would have never set out to cause me that hurt and felt terribly about it.