Sigh..
A gymnast would use a kip, that's where it comes from
Crossfit is a test of fitness, hence the claim, fittest on Earth, it's purpose is not to find the best athlete. It is claimed that a Crossfit athlete may not beat other athletes in their own domain, but will crush them in any other. Yeah, there are a lot of skills to learn, but without the skills, how could you claim to be the fittest? Rich Froning missed out on the 2010 title due to not being able to climb a rope in the final event.
The clip is from the 2008 Games, Jason Kalipa, an unknown, won back then, this year he took 2nd spot.