Horns are commonly used as weapons in the wild. Is it police brutality when the minotaur, who we can assume is armed with my statement, is already making a ruckus?
Also, I'm pretty sure horns will grow back as long as the roots is not damaged.
the staffers at the end is something anyone who has ever worked a convention or meet and greet event has always wish they could do to rowdy attendees but never could so their reactions to ED-2 is understandable