To save a ball that is travelling down the outlane by shaking the game very quickly. This results in a succession of upward triangle jumps off of the inlane and outlane walls (think of the videogame Ninja Gaiden), which causes the ball to rise back up and return safely into play.
As an aside, I have to call a penalty on myself for having to make a vertical video. It’s easy to succumb to VVS, especially when I wanted to fit as much of a pinball playfield in view I could. What we need is for Vimeo to lift their upload caps, since they support full sized vertical videos.