That was harsh. He's obviously got some issues. Hard to say if he's a hardcore racist or if he just got really pissed off and completely lost his mind.
Most professional standups have a catalog of putdowns for hecklers at the ready. All you need is one good zinger and the guy will generally shut up. A guy with Richards' rep would have had the crowd behind him, too. Its pretty rare to even see a hack just totally lose it that badly.