https://www.btimesonline.com/articles/132953/20200530/minneapolis-autopsy-knee-neck-didnt-kill-george-floyd.htm
This is a very good article. Highlights that the autopsy, which found that George was not asphyxiated or strangulated, died from his underlying health conditions, intoxicants in his system (which ones? where's the toxicology report?), and being restrained by the police caused his death. AND it points out why people disagree with the autopsy finding and demand an independent autopsy.
There was a wrestling coach who did a video reenactment, in poor taste, of the George video. He was able to breathe the entire time. I don't think that reenactment is correct mirror.
Anyway, here's what I think would need to be done to disprove the strangulation/asphyxiation angle:
Size of the cop (knee size)
Weight of the cop
Pressure applied
Duration of pressure applied
Movements the cops made
Position of George
George in cuffs
Other cops on George
Those other cops’ size and weight George’s size and weight