I watched this video thinking the camera man was going to try to snap a pic of the tag, or one of them called the cops and when he was slowing down and pointing, he was trying to alert the bike cops. Seriously... put a bike helmet to my window and you'll get a .40 S&W between the eyes.
The driver was wrong in running over the bikes, but unless its your personal life in danger, call the cops, get the tag, and let it be. Thats all you need, especially if you have video.