What Dimas is doing there though is really just a weight shift, from the heel to the ball, rather than a conscious drive off the toes. If you check out this video you can see a better example of his flat footed pull: http://www.geocities.com/ekarathanasis/Pyrros2.mpeg
There are a fair few other big lifters that pull basically flat footed - Tsgaev, Huster, Sagir, Reza.
Of course, then you have lifters like Vanev who are right up on their toes at the top of the pull, although I wonder whether this is more a function of the fact that Vanev is explosive as hell, so it’s really just a follow through motion, rather than any deliberate plantar flexion.
There’s an excellent thread on this over at goheavy if anyone’s interested - just search for “coaching the dbl knee bend”.