Ummmmmm ... yeah. [Sarcasm] Back in the bad old days of Reagan I took a Business Law class at a local JC. The prof was a practicing attorney and a judge pro-tem (basically like a substitute teacher, only for judges). IOW, not an idiot. The saying he taught was that, "Mere words do not justify an assault."
Whether Gellar's gathering is protected free speech is one matter. The wrong-headed idea that it is a provocation that justified assaulting a security guard is quite another. It doesn't.
But let's play with nads' "legal theory" a bit. That moron who put a crucifix in a bottle of urine was clearly "inciting" Catholics, if not Christians generally. Would that "incitement" have justified a bunch of Catholics shooting up the museum that displayed it? No. And they didn't.
The movie, "The Last Temptation of the Christ" was clearly intended as an "incitement" of Christians. Would Christians, therefore, have been justified in shooting up theaters that showed it? Again, no. And again, they didn't.
Nads' is the kind of "reasoning" that comes out of blinding hatred. "Reasoning" that can't withstand 30 seconds of thought by very ordinary people.