He does stand straight up when he throws and that means he is relying mainly on his arm rather than his body to throw.
One thing I noticed which I don't teach my guys is the way his right foot drags the ground on the throw. I have always felt that it slows you down somewhat. I want my guys to get their feet into position and then lift them.
I like the way he kept his feet moving toward his target on the one throw out he had to double clutch.
Pretty good overall - once he starts staying lower to the ground his throws will get much better.
One question was this the first or second game? If it's the second game I can see why he is straight up because he is probably tired. Mechanics break down when tired.