The police would've been justified in arresting everyone present the second they broke through the door with the explicit intent of disrupting the career fair. This is exactly the kind of mayhem and violence that the police exist in order to deter; if the police were unwilling or unable to arrest the protesters, the event organizers should have done so.
But that is not what is happening, and they have stated that they were at the event for a short period of time, quite possibly at the portion that didn’t occur inside the event.
The willingness to assume one version of events, and then go down that path to award consequences, is premature.
