Those details are unreported, but she was protesting, so her motives were leaning toward making trouble, and she found it. Whose to say “the gentleman” was Newt’s Security, and not a diner employee?
If the police do investigate, we'll see what role the "gentleman" played.
If it was the owner or an employee acting on behalf of the business, I don't see why it would be an issue to remove the sign or the protester, especially if not a paying customer.
Maybe we will get some answers when/if the investigation takes place.
A "left" protester is not held to a higher standard as a "right" protester when it comes to rules.
It would chap me pretty hard to see someone from the right protesting and being accosted and nothing done about it.
And we have all seen that.