Thats a good point, but I'd doubt someone would believe that one student would willingly fight four others in a bathroom, that said schools could use the students history of detentions and or ISS records for at least a clue on who done it, as this teaches the bullies that if they annoy a good student he gets in trouble no matter the circumstances and say the bad student that has been in detention and ISS before and he gets a detention and the good student who hasn't been in detention and ISS gets detention, this makes the bullie the winner as he's not going to stop any time soon but the other good student gets detention because say the bullie broke his glasses (yes I know thats a serotype but for the sake of explanation) the good student has lost as he can't see more ten feet and has detention, this makes it a win-lose situation and even if the bullie is made to pay for damage his parents may end up paying for something he did and even if the bullie worked for the money he's not stopping any time soon lastly schools know that they don't have to compensate the student thats injured as they are minorities and as such they can not sue the school district, even if the parents sues on behalf of the student the school still has better financial access, has potential evidence to the case and some schools have withheld or altered the evidence to better suit their own defence