That is unfortunate then. Sounds like he hadn't really done anything violent yet (atleast to the SUV driver) and was in the wrong place at the wrong time. But he was riding with the wrong group so i guess you take the consequences of that.
Sorry, but I'm not going to cast the entire motorcyclist group in the wrong here. If this guy didn't do anything other than riding with this group and helping out another motorcyclist, he doesn't deserve paralysis. That's pretty harsh.
Nobody says he deserves paralysis. But, as stated above, when you partake in a group like this, especially when breaking laws like running red lights, cutting off other vehicles, driving on sidewalks, etc., then when an incident like this takes place, don't be surprised if there are negative consequences. It would have been very easy for him to continue riding when they started to surround the SUV if he didn't think that was a good idea (which it isn't). He decided to remain and, as such, put himself at risk and doesn't have anyone to blame but himself.
It's an unfortunate situation all around but it was created ENTIRELY by the group of bikers. If not for the group's actions that he was riding along with, that man is still walking today.