If this were my son who had experienced this abuse, I'm not sure I would be willing to report this behavior. I wouldn't want to make my child a further target of the cruelty and bullying that takes place in High School. I realize that cracking down severely is the only way to get it to stop but reporting it seems like a huge price to pay for the victim. I'd be even more hesitant where this young man seems to have already experienced some pretty severe bullying and is going through some other difficult challenges.
This type of behavior is absolutely unacceptable but pissing off the bullies and the bully's parents isn't going to help this young man.
I'd only report if I had the ability to move or at minimum send my child to a neighboring high school.