He can let it go largely because of superior face control and a sweetspot that is out on top as fast as anyone ever.
http://www.youtube.com/watch?v=GZOwIHeV-xw#t=5m00s.....with nothing in the way of a direct route to the ball allowing for pure force across the shaft and little to no rotation late.
She does put quite a bit of force across that table with only a slight rotation once she hit the floor.