Actually, a reasonable argument should be made to the police that the hysteric both improperly made a false report to the police, *and* that he was disturbing the peace. Depending on the officers involved, the hysteric might be ticketed or even at minimum threatened with arrest.
It is important that law abiding armed people turn the tables on such people, because anti-gun organizations actively encourage them to raise a hue and cry at gun owners. That is, whenever they see a legal gun, they are told to call the police to harass the gun owner.
So do not feel embarrassed in the slightest to ask the police to address such hysterics as disturbers of the peace.
Hey, ye-uy, have you ever legally carried a weapon in the United States of America?
Couldn’t the gun owner also sue for defamation? Basically, the liberal professor was wrongfully identifying him as murderous threat to the attendees, even after the police okayed him. Seems he could sue over that.