1: He isn't harassing you. You were indeed alt tabbing for the mouse (I assume), but when u got back in the game u were still spiking.
2: That just 1 people complains about it is enough. You can still get reported for it if u spiked.
3: That you created your own room doesn't mean u can't get kicked out of it.
4: You can insult people whenever you want in game (if u get reported its your own fault), but in the report section it's unacceptable. Don't insult someone here or I just decline the report on the spot.

Anyway, Bulbasaur did nothing wrong. You were spiking so he told you to fix it. If you don't like hearing that maybe you should fix it instead of insulting.
Declined.