I'm kind of surprised at some of the self-righteousness on this thread. You can't really blame anybody exclusively, it's too simplistic:
Was he extremely inappropriate for the circumstance and context? Yes, absolutely. But you can't exclusively blame him.
He was drunk, so he should not have been on stage. He has a reputation for drunk performances, so he should not have been invited.
Also, many in the crowd were drunk, so that self-righteousness is no longer credible.
It's also too easy to blame the organizers. If they didn't put him on they would have gotten heat anyway, so I'm sure they figured it was his responsibility as an individual and artist to respect the audience and put on a good performance.
Can't blame the dancers because they wanted to put on a good performance and walking off is a difficult thing to consider and execute in the middle of a routine
In all honesty, what he did was pretty mild for what we see, say in a club... it was the context that was inappropriate. I think the girls did the right thing by waiting to see if it was for show and he was just playing...when they realized he was plain drunk they left. The organizers should not have jumped in unless they felt like he was violating their space and personal selves, but by that point the girls had left anyway so it's moot.
I'm with Jeeti, there's a better solution. The audience should simply have left. The dancers did.