This guy did something completely different, however. He ran the board about half way through the table saw then, without turning off the saw , pulled the board back very rapidly, flipped the board end for end (so the same edge was against the rip fence) and finished running the board through until the new kerf being cut met the prior kerf.
The thing that immediately struck me was that, in comparison to running the board through in one pass, his cutting from both ends enabled him to maintain far greater control over the board because almost none of the board was being cantilevered over the end of the table. He was also able to keep his hands much further away from the blade than if he had completed the cut in one pass.
About the only down side I could see to this techniques is that by failing to turn off the saw before pulling the board back he risked marring his edge or creating a kickback.
In sum, I am very intrigued by the technique but I would turn off the saw before pulling the piece back. Has anyone seen this done before? Is it a safe technique? Any disadvantages I am missing?