By the way - I played the monkey video frame by frame and saw:
1) The monkey looks really quad dominant; 2) It shows incredible plantar flexion - almost 180 degrees of extension, almost a straight line, toes pointing straight down. Once again showing how important the ankle is in the end.
Yes, the center of gravity is pretty much always lower than the bar - it's just how well you can arch your back and avoid hitting the bar with your upperback/shoulders and/or your legs that matters.