If you check the video after the assault, another teamster attempted to grab Crowder from behind by his jacket and drag him back into the crowd. Yes, it could have easily ignited a powderkeg response...
That second thug is almost ignored in press reports. This is one of the better reports that mentions him...
http://redalertpolitics.com/2012/12/14/in-defense-of-steven-crowder/
I think you make a very good point. If the second thug had managed to drag Crowder back into the crowd, the goon mob could have completely overpowered him and possibly killed him.