I'm not sure what led up to this moment of Iowa road unhappiness, but it doesn't end well for the guy who's upset. It appears that he's trying to chase down a vehicle on foot to apply a smackdown. He misses the smack, but does end up down. You'll see what I mean.
If someone does something on the road you don't like, would you follow them? And if you caught someone following you, would you stop and confront them? That's just what happened.