I don't see what the value of lying to the client would be. Just as you say, we have to be able to trust our therapists if they are to help us!

Does your therapist do this regularly? And are you sure that's what he is doing? Not asking you to share more than you are comfortable with, but I do think it sounds like an odd thing for a T to do. If you're able to, you should call him on it, as stopdog says.