Ah! Now i see what you mean. His arm whips around on plane, mine just kind of sags down after the throw.
I'm not sure what causes that but I'll pay attention to it.
My theory on follow through: everybody says you need to follow through. Tennis, batting, most sports movements. And it's true, but not for the reason stated. The follow through actually does nothing at all for the throw/hit/motion. And forcing a good looking follow through is meaningless. The reason a follow through is important is that it is the inevitable result of correct motion BEFORE the throw. If your tennis racket did not follow through to the right spot, you did something wrong with weight transfer or path of swing. So it's a good check, but it is also possible to force a good followthrough after a bad throw. Okay, enough philosophizing. I just did some work in the mirror in the basement, and think I'm doing better on the back foot weight thing. We'll see on the soccer field soon.