At first I was skeptical as well, but it turned out there is no reason to worry. He picked the right cat for the job. She was totally cooperative and it seems like she thought it was a game of some sort. It's obvious from the video that the cat was neither frightened nor angry.
In fact towards the end of the video, another cat makes a brief appearance (the guy just wanted to present her to the camera, no throwing or falling involved at all) and it serves as a good demonstration what it looks like when they're not in the mood for human shenanigans.
And they were given plenty of time to right themselves. My cats could land on their feet when dropped with about two inches clearance between their backs and the couch. And to do this experiment without thick gloves, the cat has to be treated respectfully. In short, this kind of exercise is at worst mildly annoying to the cats, and well worth it if followed by payment ham.