I would encourage you to think more critically. If you organized a peaceful protest should you be held liable for other peoples actions? He was apparently deported for speech, not violence according to the parent comment.
Restraining others from entering or leaving is no longer "peaceful".
By all means, show us the video of him doing this then. Or is he being detained for the actions of somebody else?
I have no idea if there's footage of him personally doing such things, but he's a leader of the protests, and one of the people negotiating on behalf of the other protesters with the university. He is most definitely taking part in occupying part of campus illegally, so his ass should be deported.