Here's the 50 footer spinning....

http://media.putfile.com/OL50_spin

Looking at the 50 video, looks like he was running trimmed out and as the boat was going straight then as he went into the turn looks like the trim went got tucked in and the nose lowered created air lift on the rear and spun, most stepped bottom problems come from a driver turning the boat and triming the drives in that allows air to get trapped in the rear and creates the back to lift. With a step bottom you respect the turn and make it a little wider and never trim the drives in, the boat will act like a jet ski and spin out. But on another note the 45ZX is not the fastest boat but she sure can crush waves just make sure you have the drives checked, the biggest problem if the boat has been launched several times over big waves the middle drive suffers from all the torque and weight of the boat. She should run with 500s about 80mph