Bad manners are not a crime, but people often commit crimes due to their bad attitude that is engendered by their chronic bad manners. Sorry, but this kid refused lawful requests to comply with campus rules which then led to his criminal acts of trespass and resisting arrest.
No doubt he thinks he's a crusader, but he's just another dumbass kid with a limited understanding of real tyranny.
You keep ignoring the FACT that he was leaving when prevented to do so by being assaulted by a cop. If you were leaving someplace and were prevented from leaving by a cop would you be trespassing?