I think the Rifleman has his work cut out for him when it comes to Dwight Howard's free throw form. The following is my analysis of the issues and corrections:
Dwight uses too much wrist snap. I'm sure every good jump shooter/free throw shooter knows that proper backward rotation makes the shot land softly on the rim, giving errant shots a better chance of bouncing in the basket. However, Howard seems to have taken this to the extreme. He uses almost all wrist and forearm action to give the ball its height and trajectory. However, those muscles shouldn't be used for those purposes. The legs, shoulders and triceps (ie the big muscles) should be the muscles that generate the power to get the shot to the rim. The hand, wrist and forearm are the fine tuning muscles that impart direction and spin.
I've read and listened to interviews of Dwight Howard and he says that Chuck Person has him focused on his follow through. The end result in games so far (and I know its still a work in progress) looks like Charles Barkeley's golf swing. Dwight steps up for the free throw, shoots his free throw with a flick of his wrist, then makes an exaggerated follow through that is delayed a 1/4 second or so after the shot is gone... it looks downright strange.
Dwight needs to use his legs, shoulders, and arms. 1) Raise those chocolate shoulders. 2) Finish high (Dwight's finish position has his hand right on plane with his face. Way too low. He should be finishing like Wesley Snipes in White Men Can't Jump when he leaves his hand in the air saying "its so pretty. I'm just going to leave it up there."
Shoot practice free throws with the ball way down in the palm of his hand, basically forcing him to shot put the ball. Shot putting is the other extreme: basically uses little to no wrist action and all legs, shoulders and arms. This will help him use more of the body that he is missing.
Shoot rainbow free throws. Shoot practice free throws 20 feet into the air. His current form won't allow him to the that much height on the ball, but proper form will.
I'm just venting on something other than coaching changes, so no flames please.