Quoted from northerndude:
Lot's of it happening here. No lane changes, too fast fro screen info. one instance there is two balls on one flipper. A few times its random and no ball even on a flipper.
I'm thinking more a built up habit than anythning.
Go to the 15 second mark in the video. You'll see that like FatPanda said, the two balls on the right flipper aren't completely settled. Giving the game a wiggle also wiggles the tilt bob. Flip the right flipper and you're liable to go a little overboard and now you have a jail break. Hitting the left flipper a pile of times helps get them into a two ball trap so you can then cradle separate.
You can watch the player, he gently hits the right flipper to get them moving and then hits the left flipper a bunch of times really quickly to keep them moving if possible. It's a delicate balance to get them into a manageable position.
I only watched the first 30 seconds of the video, so that's the first instance I saw.
Edit -> I watched some more. A good bit of it was either nervousness or impatience. There were also times where the player was trying to get that extra inlane. The ball rolls up the flipper, hits the switch, you hit the flipper quick and switch lights to the other inlane thereby getting a two for one.
I find myself doing that out of habit even on games where the ball either doesn't have enough momentum to get up to trip the switch or games where there isn't even a movable inlane light. It's just habit at that point.