Intense scene, well written.
I'd say he has the information and ability to attend some other magical school he wishes or to drop out of sight altogether. He has the money and the brainpower to do either, but most authors stick him in Hogwarts so they don't have to think up a plotline.
His best bet would be to go to ground somewhere as it's easily apparent that the Headmaster is up to something and being in his power isn't something that would be good for him.
He's definitely a Puff with his attitude.