Originally Posted by nubikeshop
...There's something called the "eggshell skull" doctrine-- in layman's terms, it means that if someone does something malicious or just plain stupid, they are completely responsible for the actions that follow, even if nobody could have predicted them...
Close on the "eggshell thin skull" doctrine. However, not quite. What that doctrine refers to is when you injure someone, but because of a preexisting condition, the injury is much more severe than you could have expected, you are liable for all damages even though the normal, healthy person would not have been as severely injured.
In this case, the legality of his operation of the bike may or may not effect recovery from a legal perspective, but if it is illegal, it's not going to help if you have to go to a jury
...but as i said- take it to the school. People sue way too much and it is not as satisfying as people think it is going to be...and it is not going to make you rich....or any significant money, for that matter.