There are many guys who know biomechanics better than me that could educate him, so not thx.
All it takes is being engineer and learning human anatomy from what I hear. Smarter physiotherapists also know their shit.
Actually, not really...
People tend to over think things, especially very smart people. The smartest people realize it is very hard to simplify things...
Squats--too many variables to say someone "doesn't know how to squat". Take in account, height, leg length, genetics, weight, the weight you use, reps, sets, and width of legs, and depth. You have a dizzying array of variables that may come into play.
PL and bbers tend to squat differently, different goals.
And Phil's quads and hams are pretty damn good (dense, detailed), regardless of the "boatload of drugs.
Check his first vid, where he had hurt himself on lying leg extensions (something you don't see on video) and check his sets and reps. He does what he needs to do.