Quoted so it doesn't get missed.To noob lurkers that may be about: if someone is lifting a sum total that approaches the weight of, say, your mother-in-law or something larger, then stand the hell back.
The only two times in my entire gym life that I lost my temper and went-off on somebody were both occasions similar to what you describe. WTH is wrong with people anyway; are they deliberately trying to hurt themselves or someone else?
Bodybuilders using Back Squats really need to think about what it is they're trying to accomplish with this exercise, and then make adjustments to get that specific job done. Just piling on the plates and moving them up and down will only take a guy's legs so far.
On the 'plus' side, maybe it beat the "alternative."
I remember seeing DeMayo on "Flex Magazine Workout" a couple of times, and being blown away by the size of his legs comared to his age.
Things should have turned out better for him.