OK, fuckwads, no more kilo talk. The world record is something like 950. And that in real measurements.
Also, like others have already pointed out, all that you could say is "wrong" with his form, is the rounding of the lower back. It's not ideal, but I've said it before, and I'll say it again, lots of good pullers have done it with a rounded back, look at The Kaz.
Especially when you get up to being rather large, like that fellow, it gets harder and harder to get down to the bar with a neutral back position, that's part of why he grippped n' ripped.