[davidb_]

That's a neat trick. Based on the article and rewatching the video, he's not actually flipping the coin.

> In Section Three we prove that the angle ψ between M and the normal to the coin stays constant. If this angle is less than 45 ◦ , the coin never turns over. It wobbles around and always comes up the way it started. Magicians and gamblers can carry out such controlled flips which appear visually indistinguishable from normal flips.

[steve19]

He refers to it at the end of that video clip as tossing. looking closely that's pretty much what he is doing. it looks like he might be flipping it once during the toss for effect. Such a slow rotation allows him to easily catch it at the right moment.