Its new jersey. I think they knew they were pretty safe from being shot at by the homeowner. Any display of firearms in new jersey, much less shooting them, will get you serious jail time.
You're assuming that a man who hurls racial epithets at his neighbors and has to be restrained by the police from personally confronting the protestors is thinking rationally. New Jersey has a hunting season so they have guns. He may not have had an AR15 but you can do a lot of damage with a shotgun if you're properly motivated.