Doing this kind of stunt on a closed course is one thing, but doing it in traffic where someone else could get hurt? That's just stupid.
He's lucky all he lost was some skin.
He's lucky he fell away from the bike, not under it, and that both he and his bike made it off the road so that no one else got injured. If you're going to pull this kind of stunt, you have to have the skills & the proper equipment (read: leather!) to do so.