Googley, I completely understand why you'd be mad. It was uncalled for and unprofessional. At the same time, the advisor really didn't know what he/she was talking about; making a snap judgment based on incomplete information which is just as bad as the effect it caused. Another example of speaking before thinking, inconsideration, and unprofessionalism.

You didn't deserve this at all. Know that. Ignore them, really. You know what is true.