True that. There have been successful lawsuits for obstruction of first amendment rights for similar actions but I’m sure most people wouldn’t go through the trouble of that, or have the means to.
I could be misremembering the details, but I read about a case of a cop wrongfully arresting a Black Panther member in the 60s or 70s, his friend shot the cop, and his charges were dropped because it was determined to be self-defense. I think the cop was plain-clothes which would have made a difference I’m sure, but I can’t imagine that happening today in any US court.
I have noticed when I’ve seen protests with armed groups involved, even just a handful of John Brown Gun Club members for example, the police are much less willing to mass arrest or escalate, for obvious reason. Though I think the student protests in this instance are going for optics of peace and non-violence so they probably don’t want that.