You really had nothing better to do than repeatedly move your pecs and wrists and press shift space? :P (Actually I still can't figure out how you do that. Even though it looks like you just move your wrists and pecs, I tried that and it doesn't work)
Heh, it has something to do with repeatedly grabbing and releasing his head. I guess the expanding hands going from grab to ungrab cause damage to poor uke's brain.