I've had a few different kinds of instances where the therapist told me something negative.
One was in a negative, judgmental way. The therapist was angry and hurt, but wouldn't share that with me to work it out. It was very, very hurtful, and not therapeutic (except to understand the range and variation in human behavior). I don't think this is therapeutic, or competent therapy.
One is where the therapist, with a great deal of understanding, support, and genuine concern for me, and willing to work with whatever response I have, suggested (not asserted as truth) that I might not be seeing something. I was okay with that and it was helpful.