There's a common misconception that if someone can talk, that means they can breathe, therefore they're not being choked/in danger. Being able to talk means their airway isn't completely blocked, so they won't be passing out and dying in a very short time frame. However it is still possible that their airway may be restricted enough that they aren't getting enough oxygen to maintain consciousness and life indefinitely. In such a case, you would expect unconsciousness and death to take a while, as is also typical forAs was pointed out, he could talk, saying that he could not breath
I believe Floyd was on his side during at least part of the process. If you kneel on the neck of someone who is on their side, then their own shoulder on the opposite side can apply pressure to the artery on the other side.Its also impossible to to do a blood choke, with only the one knee. If you train BJJ or Judo or any art that teaches collar chokes... try applying a collar choke with only one collar, leave the other side of the neck alone. Sure, you cut off the blood from one side... but you will never choke a guy out, unless you have at least both sides of the neck.
In any case, we know that Floyd was not subjected to a complete technically correct blood choke as we would use in judo or jujutsu get a tap, because if so he would have passed out in seconds. However it's entirely possible that blood flow was restricted significantly, which would have reduced the oxygen reaching his brain, which would have already been reduced by both the restricted airflow and the pressure on his chest.
I believe J. Alexander Kueng had more of an effect on killing Floyd that Chauvin. J. Alexander Kueng was actually helping to prevent Floyd's chest from fully expanding.
This is entirely possible. The officer on Floyd's back restricted his ability to inhale and keep air in his lungs. The officer on his neck restricted air and blood flow. Maybe it took both of them to murder him. Maybe one or the other might have done the job alone. It's not exactly the sort of thing we want to do controlled experiments on. I do agree with your conclusion that there needs to be better education and policies in place to reduce incidents of positional asphyxiation.In fact, I would venture to say that if everything were the same, except that Chauvin walked away, no knee on the neck, Floyd would still have died, from being held down by the officer on his back. Taking the knee off the neck, would not have saved Floyd. Taking the officer off his back, and putting him in a position where he could breath might have.