Ok. As I said, I'm a layman -- what do I know?
But there was a case some years ago in Pittsburgh -- a man died after a policeman stood on his neck. Story was, the man was gasping for air and saying, "I can't breathe." I had heard afterwards this method of restraint was going to be outlawed nationwide because it was too dangerous. Maybe I was wrong and it's still in use in Minnesota. I don't know -- just seems too dangerous to me.
I have twice been subjected, with very much prejudice, and air was never the problem. Primarily, it staples you down... Similar to sitting on the head of a cow or a horse. Secondly it is a pain hold... the cop leans in a bit, and you will wish you were dead. It hurts like a holy terror. Settle down, and the cop lets up, and so long as you don't struggle, everything is fine.
As in this case - Watch closely when the man lifts his head a bit... his neck moves up... he ain't being bolted down hard.
Two cops I know gave me the same observation, and granted, these are cops, so you can suppose where the bias is... Both said it was a textbook swarm to subdue him, with the guy remaining on his head to keep him down.
Evidently the cops called for EMT very early on, so they knew he was having problems... The speculation being that he was probably being kept immobilized to keep him from further harming himself... Fairly typical with crack zombies, as an instance given... That is why he would remain on post until the EMT arrival. Neither one considered the situation to be out of the ordinary, to include the neck hold, with the exception of the failure to render aid.
And I would agree with that... I think the cop has to answer for that failure to render aid.
That jibes with reports that the guy was lit, and fought getting put in the car. The ensuing struggle would leave him exactly as he was, waiting for the bus.