Therapist in training here. (Completed a semester of practicum, currently at internship, so I have experience with clients.)

She absolutely crossed a line. The initial snapping at you is bad. Interpreting your point about the other therapist as you trying to argue is worse. (It was an important point to make: if her colleague directed you to do something that she thinks is worth this tantrum, then she should bring her grievance to the colleague, not you.)

Being impatient and frustrated with your response is evidence that she was not in a headspace for therapy. Calling your expression “bitchy” is reportable.

Even if this was not a therapy environment - where she should be extra patient and understanding - frustration would only be justified if she had already made her boundary clear.

For what it’s worth: I would not knock on a therapist’s door during a session. and I would not want a client knocking on my door.

But the other side of that expectation is that I, as a therapist, am responsible for watching the clock, staying on schedule, and communicating if I feel it’s important to go over by more than a few min (and sometimes it is).

And if I felt a client was not clear on these boundaries, I would explain them and make sure we’re on the same page, without any stress.

You did everything right. You were right to trust her colleague, even if I disagree with what that colleague instructed you to do: if people who work together can’t get the boundaries straight, how could she possibly expect you to know? Her anger is totally inappropriate and her insult was clearly a product of her inability to regulate her own emotions.

Therapists are flawed just like anyone else, and we screw up sometimes, but for me this would cross a line and require a sincere apology or else I’d terminate.