He tends to use his forearm in lieu of the wrist. Of course this does not work well. If the hand is not bent back to near 90 degrees to the arm, you can not flick the ball with backspin and with the proper arc. His arc's are flat resembling the shot of an old Philly player, Woody Salisbury, who banged them in from the outside. The cure for this problem involves flicking or waving the wrist back and forth like you are waving good-bye.
Emphasis needs to be placed on the flick backwards and then just let the hand go forward.
Shooting properly is no little endeavor, and every player at every level especially the pro's, need to practice at least 10-15 techniques and drills daily to improve and keep their shot consistent. Detroit even though they initially gained a big lead with good shooting, showed signs that they would fall apart in a pinch because of horrendous defense. Later in the game their defense picked up now and them, but to no avail. Proper defense starts out with proper defensive position and eyes on the ball. Let me explain the importance of defensive position using an analogy.