For arguments sake we should probably rule out the knee on the side of the neck for 8 minutes as playing any role in his death. We should probably conduct an experiment. Any volunteers to do the full 8 minutes? Anyone? All right, how about 7 minutes...anyone? Someone? Bueller?
Try it on yourself, and let us know the results.
A retired officer I know demonstrated the technique on his wife to show her how deceptive the video was.
He asked her: Can you Breathe? She answered: yes.
He asked her: Are you in pain? She answered: no.
He asked her: Are you in discomfort? She answered: no.
He showed her how only light pressure was needed in the technique, to keep her from getting up.
He showed her how in the video, it appeared the knee was putting pressure on the neck, because of the camera angle, when it really wasn't.
I volunteer to be in the same position, with the retired officer demonstrating the technique on me, for nine minute. I would just take a nap.
Unfortunately, the officer is 2500 miles away.
The technique is designed to allow control of a person on the ground with minimal pressure.
You cannot tell how much pressure is being applied, by the video.