I'm pretty sure this is a good habit to have, as long as the motion is natural and not over exaggerated. When shooting a long pull or a snake the concept is to get around the ball, by sending your momentum in the opposite direction when you shoot the ball you're going to get a straighter, if not a cut back, shot. It's hard for me to explain since I wouldn't consider myself good enough to have a consistent shot, but if you pull the ball and shoot with your momentum still going in the pull direction the ball will still stray slightly more to the pull side. When you change your momentum the moment you hit the ball, you send the ball in the opposite direction, sneaking by any defender and catching the corner of a goal.
Hell, I'm no good at explaining things, but if you look at some videos of pull or snake shots on youtube (there is one good one that's like 24 seconds of a slowed down pull shot) you'll notice that they come around the ball, switch momentum and shoot. When I first tried starting to shoot really long pulls I noticed that everything I hit would slam promptly off the near side goalpost, I'm pretty sure this was caused by the lack of the 'recoil'.