If you got kicked out of your gym for hurting your training partners, it almost certainly wasn't a one-time thing. Screwing up that guy's knee was probably just the last straw. Maybe you should take it down a notch in training.
Don't take this the wrong way, but is there possibly more to your story?
You train somewhere for years (enough time to earn a purple belt) and are the highest ranked student in the gym beside the instructor.
Then you hurt someone on accident one time and your instructor tells you that you have to leave without even hearing your side of the story?
Something doesn't add up. Also, have you been bad mouthing the gym or your instructor to anyone? Either they are being completely irrational by not even letting you come inside the door to pick up your girlfriend or there is more to your story.
Anyway, I would of just waited in my car to pick my girlfriend up. Going back inside is kind of weird after that kind of split.
Don't take this the wrong way, but is there possibly more to your story?
You train somewhere for years (enough time to earn a purple belt) and are the highest ranked student in the gym beside the instructor.
Then you hurt someone on accident one time and your instructor tells you that you have to leave without even hearing your side of the story?
Something doesn't add up. Also, have you been bad mouthing the gym or your instructor to anyone? Either they are being completely irrational by not even letting you come inside the door to pick up your girlfriend or there is more to your story.
I would listen to inside the Bjj podcast as they are going to be all over this.....
I would talk to the instructor at the new gym. Start by explaining (honestly, without exaggeration) that the guys here are much better than at your old school. You used to dominate everyone but here you get tapped by people you would expect to tap. That will flatter him, but it's the truth.
Then you tell him your thoughts, like you don't think it's fair to the other students to keep your purple belt, or you feel uncomfortable, or whatever your justification is. Most likely he'll say don't worry about it stay at purple, and he'll just wait longer to promote you until you've caught up. That's what happened when I came to my current school as a not-so-good blue belt. Or maybe he does the opposite and say sure, you can wear a blue belt here. And then you kind of got your wish. But don't just throw out your belt and start wearing a white belt, that would be kind of weird.