knockout via kick

I tend to think that using a kick to knock someone out is implausible at best—not least because you often have to turn your back to your opponent—but there are plenty of videos out there, many showing an MMA context, in which someone executes a beautiful kick and scores a knockout. Speed, strength, timing, and coordination are all factors—and a little luck helps, too. Here's an nice example of a knockout with a reverse* kick:

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*The video title calls this a spin kick, but I was left wondering whether this was a reverse turning kick. In a spin kick, the leg is generally straight, and it whips around in an arc. In a turning kick, the body turns partially, and the leg is pistoned backward in a horizontal stamping motion. When you watch the video above, you'll see, at the very last moment of the knockout kick, that the leg does piston out a bit, and the kicker's foot slams full-on into the opponent's face; had this been a true spin kick, the foot would have whipped across the opponent's face like a slap. Before that moment, though, I can see why people might call this a spin kick. But I'm not totally convinced.