You are presuming events which have already been shown to be false, by the autopsy.
The knee was not cutting off blood from the artery. It may look like there is a lot of pressure on the neck, when there really isn't.
It explains a lot about the officer's facial expressions. If he knew he was not applying a lot of pressure, so he would know the bystanders simply do not know what they are talking about.
What many have assumed was indifference to the condition of the 6'7", extremely muscular man he was controlling, who it appears took 3-4 officers to get prone, because he was fighting them as they tried to get him into the car, could easily be indifference to the bystanders' attitude, because he knows they do not know what they are talking about.
A lot of assumptions going on.
It is why we have an adversarial system, so each side can present evidence and explain what happened from their knowledge.
It appears a lot of assumptions which were put into the narrative of the video, are turning out not to be true.
Once again did you even bother to ask your officer friend if he uses the same technique of his suspects?