I am going to be the devil's advocate for 2 sec. Why was this child beating a blind kid? Was it provoked? I remember growing up with 3 brothers, and while there was bullying, there was also injustice in the discipline received. One brother would provoke the other (usually me) to anger and that brother (me) would take the matter into his hands the way he knew how. Obviously that means picking up the nearest object and using it to correct the provoking brother's behavior. That would earn me x amounts of ass beatings for being violent towards the one that deserved it.
I say this because I don't know the whole story, and if you do, please share. If it is a case of straight bullying, then the kid got what he deserved, and the protector was wrongly judged. I also know how kids work in high school, and it is rarely a single sided situation. That being said, high school administrators have proved to be unwise many times before.