If he gets pissed off about a normal question by a person interested in his/her own health, he should do something else. Clean toilets, stuff like that.
A lot of hip bend, not a lot of knee bend, notice how he stays on the toes, there's no ankle collapse, a ton of foot and calf strength to do that considering the tremendous amount of power that the foot is receiving from the upperleg.
It's funny.. each sport has a majority of strength coaches who "do shit wrong", because most of them focus on some kind of distorted specificity to the sport.. however, you then have football strength coaches who may not know much of anything about the science, but they are all about: get your bench, squat, and olympic lifts up. It's just tradition and it makes sense because of how brutal the game is. If that was the default mindset for basketball (simply getting STRONGER), it would be scary what the competition would look like.
Those plates look a lot like the ones in that crossfit gym I once went to, when I deadlifted my 184 kg deadlift (405 lbs).
In that gym there were plates as "big" (in diameter) as a 25 or 20 kg plate, but they were 5 kg. They were like that for weak people to do snatches and cleans off the floor from the "correct height" (question remains - what business do weak people have with Olympic lifts?).
So there's a great chance that except for the thicker plates which might be ~15-20kg, all the others are 10 kg or less (probably 5). It looks like 20+20+10+10+5+5 on each side, which is 70+70+20 = 160 kg.
But I hate how his feet are not exactly in the same positions (weight distribution) and his lack of control of the movement.
This makes me remember Brandon Roy training with his trainer and the trainer allowing him a tremendous amount of knee valgus occuring during plyos and lunges and all that jazz. Unbelievable.