The article clearly does not contain the full story. The article says the bikers surrounded an SUV and then a “biker apparently cut the driver off and slammed on the brakes just before the SUV bumped his rear tire.”
But if you watch the video, it looks like the bikers are already chasing the SUV before the biker slammed on his brakes and got bumped.
Something happened before the video begins that started all of this.
See Post 40.
I agree. On the video it looks like they were stalking the suv for awhile. It really looked like a scene from Mad Max.