I preface this by saying I'm a huge admirer of Tim Ferris. That said, when reading the 4 Hour Chef, I was struck by this claim: "In less than 12 weeks, sans coach and following a printout from Barry, I went from a max dead lift of 300 lbs to more than 650lbs.
The only video I could find was this of him doing a rack pull from well above the knees. Technically, he could say he pulled a lot of weight. His hands were on it, and it moved a couple of inches. Realistically, though, powerlifters say "they pulled" something when they deadlifted it, off the ground. I'm pretty sure you could find any number of people who could pull 100-200 lbs more than their real deadlift max if they pulled from above their knees on a Smith machine.
>>> Ferriss, Timothy (2012-11-20). The 4-Hour Chef: The Simple Path to Cooking Like a Pro, Learning Anything, and Living the Good Life (Kindle Locations 516-517). AmazonEncore. Kindle Edition. Footnote Three: 3 Pulling from the knees using a double-overhand grip (not hook) without wrist wraps. I could then do 475 from the floor for repetitions. See “Effortless Superhuman” in The 4-Hour Body for the full program description.