It seems to me there are several different ideas floating around on this thread and some people are over-identifying with the person who got the appointment even though we have no idea whether that person cared which office they were in or gave any thought to OP at all. I believe that person probably did not give the OP another thought - I personally would not have been worried about the person who was sitting in the t's office and moving to another office would be no big deal to me at all. Also the t can take care of himself and if he chooses to try to discuss the situation with OP, then I fully believe he can or should be able to take care of himself. And I do believe the t should have some consequences or at least remorse for his double booking. A client's time is just as valuable at the ts.