I have seen video of this, and some sites don't show all of it. As a SUV owner and a motorcyclist, I can't say that either side is without fault.
If you look at the video, you will see that there is only this one vehicle (SUV) on the road anywhere remotely near the bikers. If fact, it is the only non-motorocycle I have seen in the video. I strongly suspect that the bikers were out on a group ride when the SUV barged into their pack. Now, I have been on a number of escorted (often time police escorted) organized runs when other traffic is blocked for the motorcycles, and I have bikers and escorts do what was done here - slow and stop in front of the offending vehicle until all bikes are past.
So, for the start of the incident, the SUV owner may likely have been wrong by breaking into a pack of bikers (at least stupid if not wrong), and the bikers were wrong in stopping the SUV like it was an escorted run. Now, what you don't see in a number of the postings of the video is that a biker very quickly stops right in front of the SUV and gets bumped. So was that biker a fault for cutting off and dramitically stopping right in front of the SUV on a highway, or was the SUV wrong for driving into that biker and break the biker's leg? Flip a coin on that one as far as can I see from the all the videos. But as long as the SUV driver was not doing a hit and run, there was no need for the bikers to come after him (which they did right after the initial accident). The bikers were in the wrong there. However, with bikers coming after him, I don't blame him for running over a few bikes (not bikers) to get away. I would do the same.
Once he took off, I don't blame the bikers for following him, but beating the guy was just wrong. Hold him for the cops and let the cops sort it out.
Using the helmet to break the driver window is pretty stupid, the guy just destroyed the inetgrity of the helmet and will now have to shell out some bucks to get a new one if he values his own head.
k_enn