While charges and reality don't always sync, that is a pretty nasty list. It's one thing not to understand CA laws and to be in possession of gun in a way that is legal in most states but illegal in CA. Although you'd have to be pretty stupid not to know CA gun laws are very strict and to make sure you are following them.
If any of things on that stolen list is real, the team and the league are going to come down hard on him.
Not sure how the cops would know that he knew the gun he had was stolen unless he told them.