"After Miller walked away, Hopfinger said, he was surrounded by Miller supporters and security guards and felt threatened, so he pushed one of them away.
"Fulton said the man shoved by Hopfinger was not hurt.
"Hopfinger said that after he shoved the man away, the guards grabbed him, cuffed his hands behind his back with steel handcuffs and sat him in a chair in the school hallway, Hopfinger said."
It's that shove that bothers me here, that makes a story possibly, just slightly, morally ambiguous. At the most charitable level, I think it's possible that people who go into private security might see a shove, whether justified, even committed by somebody who was surrounded and felt threatened, as something that they were responsible for dealing with (not to justify the response, but this is possible). It is also possible that at least one of these guards is a thuggish authoritarian type looking for an excuse (thuggish authoritarian types usually are), and by shoving somebody, the reporter gave him the excuse. At the very least, that shove gives the security guards a chance to claim that the reporter's actions justified their action, whether it is true or not. They can claim their actions were justified by an assault, a disturbance, a burgeoning situation, whatever they want. They are probably not right. But it might look like it could.
I am not writing this to defend security guards, hired by a political candidate, who detain a reporter (and certainly that video shows a person threatening to detain somebody over less than a shove). But the story illustrates the need for those in the moral position to restrain themselves from any display of force. Any element of force can create the possibility or even perception of possibility that one is in fact in the wrong. Nonviolent resistance allows those in the moral position to keep the moral position.