Perhaps he could have gotten himself arrested but the video makes that fairly unnecessary.
First, we don’t know for sure he would have been arrested. Most of what these bullies do is try to intimidate. I’m reminded of Quannel X leading some open-carrying black panthers into Joe Horn’s neighborhood (the Texan who exercised the castle doctrine and shot the two black thugs robbing his neighbor’s house) to intimidate the people there, all of whom supported Horn. Quannel and his boys turned tail and ran when they were drowned out by motorcycle and truck engines being gunned, people surrounding them with menacing shouting, etc..
It’s been my experience that pushing back against these people usually backs them down, especially when they are acting alone. They’re cowards and bullies, and they think white people are afraid of them. I’m not.
I just wish I’d had the opportunity that the man with the sign had, and I’m a woman.