Yep. If, after falling down, he had made a joke of it, it would be no big deal. Look at the snowboarder on Letterman who had an accident outside the studio -- she came back the next night to joke on the show! Instead, Kerry's so full of himself that he declares he never falls down, and curses about a Secret Service agent to boot. And this is on his vacation!
Apparently he's short on sleep. Or something. Maybe he hasn't been taking his Flintstones.