Good video.
Last part is interesting, where he talks about pro baseball players and how they talk about swinging with their hands.
The same goes for ball golfers, and in disc golf pros talk the same way about the elbow instead. When you fall, brace, shift, resist and release the throw (on auto, as a kinetic sequence) the only sensation left is the leading curl of the whip. That curl being the elbow for us. Hold on to a club or a bat and that curl is moved out towards the hands.