You can even tell from these two pics that one guy is much more natural throwing the ball.
The receiver is at the same spot coming off the shadow.
Follow the hash marks because that's the direction of the pass.
Now look at the lead foot for both QBs in comparison.
Tommy's front foot is to the side, planted, and pointing at the receiver. Even though he is throwing it in front of receiver (the route).
Bush has his front foot in front of him, and pointing to a spot in front of the receiver.
Don't know if it's natural or something worked on, but just off of that, AJ will be on target more often than Tommy. It definitely looks proper.