hahahahahhaaa, Derek Farnsworth would get crushed by 800 pounds, it would drive him through the floor, who told you he squatted that?
I saw a video on the net, it was on Derek's site, about 6 years ago. Not sure if the site even exists still.
The video I saw was 700+ though, not 800. He did a very deep squat, but for him that means moving as much as 7-8" total.