... it just looks really bad when a cop lays his knee across someone's neck when they its noted that the individual is assumed to be clinically dead.
Sure. It looked bad. That's why, when this first occurred, you had near universal agreement that Chauvin was at fault. But, like always, you wait a bit. The evidence comes out, and the full story is not nearly as clear.
But that was the point of Crowder's demonstrations (2 total). If this position really cuts off the air, or is a "blood choke", then let's give it a shot. He tried it twice, with more weight. It *looks* bad. And, it is painful, but not deadly.
Granted, the jury was never exposed to any demonstration like this, and I think it would have been a great demonstration to have, right there in the court. Let's just see what happens when you take a man, whos not about to explode in 5 minutes, and place him under that hold.