We did kick him for harassment, I still consider reporting him, but if they look into the chatlog (if they can) the discussion between the "teacher" and the "unwilling student" got quite unpretty towards the end.
And I don't want the "teacher" getting punished for losing his temper after 35 minutes of this insanity.

Gormogon, I really wish you get this what I got.
One complete new to the 50ies world DD
Another DD (same class) that performs so poorly, that even if you never played the class, you know something is going on, even poorer than the other
The "teacher" that calmly tries to tell the DDs how to improve. Not impolite, not polite, neutral. Not in condescending manner.
And you in the middle of it, wondering why the dungeon you even rushed in REALLY bad gear takes that long.

Would you really say "ah whatever, I am not paying his subscription, so he can play like he wants, even so it diminishes my fun?" or would you be asking friendly what is going on.