Of course, that same dude probably did that a dozen times and got less positive reactions. Being a leader means having the guts to get rejected. If you carry on after rejection because you are driven by your own joy and not social feedback, you may start a movement. Don't expect this to happen on your first try.
If you search YouTube for 'Sasquatch Dancing Guy', you'll see that the same guy in black shorts in several different instances of dancing (other times/songs) like he is the lord of the dance. Other video segments of the same Santogold song show he was dancing all the time.
But does that invalidate the mob/snowball/inspiration-to-act effect captured so well here?
To answer your question, no, that doesn't invalidate the effect captured here. However, if you are trying to duplicate this effect, you should realize that these things are probabilistic, and not deterministic, like so many phenomena in human society.
Maybe it took him dancing to all those other songs to get his first follower... Surely he had been noticed by many at the festival before he was unstoppable.
