I know, right?
yeah I really don't know what's going on here, but it sure looks like his shoulders are stiff during those cuts. That's the usual thing that I find causes my shoulders to pop up and rock forward when I cut. Not sure why he is jerking his bokken to a halt in front of him.
Seriously though are you sure this isn't a "what not to do" demonstration?
I assure you that this is not a "what not to do" demonstration. Could you post a link to a video which demonstrates the first suburi as you believe it should be done?