No you have it wrong.
You totally forgot about the part of the bikers kicking his vehicle and slashing his tires when he first stopped after the biker cut him off and slammed on his brakes and got bumped. That is clearly on the vids. At that point in this incident it was a minor traffic incident and no one was injured. The bikers chose to expand it into a violent confrontation.
You completely ignored that fact that they had no legal right to pursue him riding in the oncoming lanes of traffic, on the sidewalks, on unlicensed bikes and quads, and then surround him and stop him. This is also on the vids. Then you continue to stray from the truth in implying that somehow this moron had a right to shatter his side window, endangering his wife and small child, then rip him out of his vehicle and beat him. When that happened the SUV driver was caught in traffic and could not escape but the biker took it upon himself to be judge, jury, cop, and the giver of punishment. Wrong, totally, completely, absolutely, and not lawful.
If It had been me, at least the guy swinging the helmet guy would have suffered a double tap to the center of mass when he attacked me with his helmet. When you watch the vid there can be no doubt that the biker was using it as a weapon with the intent to cause bodily harm.
In the free parts of America an armed response would have been easily justifiable. Unfortunately, this businessman and his family live in NY.