Pardon my ignorance as I never pursued strength-specific training, but is it possible to estimate what an unspotted 4 x 405 would translate to in terms of a 1RM?
It's tough, but I wouldn't be surprised if it wound up in the #430's, #440's for most people. It would also translate into a near #500 flat. I'm positive he'll have to up the dose or get heavier, but I don't doubt that he could probably do it. He put up some very surprising, albeit ugly, numbers in the shoulder press, and he is built heavily in the muscles that make presses go.