It was the police who broke the law, not the student, first by grabbing the student as he was walking away (why didn't they just let him leave?), and then by tasering him for refusing to get up. A taser is used to take someone down, not to make him stand up.
Besides, after being tasered it is difficult to stand up for several minutes (or even impossible for a weaker person). It could very well be the case that he physically wasn't able to stand up as they were ordering him to do.
The student only broke a university bylaw by refusing to display his ID.
I don't quite get the legal status of University rules. Some universities have their own PD, and they are real PD with all the legal authority that police have. It's interesting. We have a university here and I've seen some trials in district court. It will be interesting to follow this if the charges against the student are pressed.
But if the student walked away when given a lawful order, he HAS broken the law, at least in most jurisdictions.