If anything, it could be conformation flaws and over reaching. He's hitting his front leg with his back leg, that's over reaching. His back or hips could be out of place if he's hitting his front leg with the opposite hind foot, but we won't know anything without a video or pictures. It could also be that he's being ridden that crookedly. We have nothing to go off of so we can't give you a solid opinion.
And those who were seen dancing were thought to be insane by those who could not hear the music