Next time out I think I am going to throw a few "back up" balls just to look at my hand position. It does look like my trail leg is coming into play more often than not since doing that one step drill.
John, just make sure that you are keeping your hand to the inside of the ball and not in the handshake position to throw that back up ball. The point of the drill is not to actually throw a back up ball, but to keep your hand to the inside of the ball through to the release. Like Lefty said just throw it like you do in your practice swing. You turn it when you are letting the ball go because your brain is telling your wrist and hand to do something to the ball to make it hook, STOP TRYING TO HOOK THE BALL. Trying to hook the ball is killing your game and killing the hook as well.
Next time you shoot a video, I would like to see you hold the ball until your left foot starts on your third step instead of starting the ball with your second step with the right foot. You don't have a big huge push away which is good, so you can start the ball a step later and this should help get your right hip out of the way on the back swing and help you get in a release position before the ball passes your right hip on the release.