>>A small number of people were responsible for the riot. They were dressed in black with black masks.

I get an impression of bovver boys possibly with nothing to do with the university, who saw the protest as an opportunity to cause mayhem. Some drunken or over-excited louts then celebrated the escalation, which many an excited youth would have done in our day when everybody didn't have a camera in their pocket and there was no internet for a video of privileged students squealing with delight go viral. Meanwhile the person who pepper-sprayed the young female ticket-holder was not wearing a mask and seems to have been extensively photographed by other disgusted protestors.