Put an MD up on the stand. Ask if the MD could give the Prosecutor enough fentanyl to raise his blood level to 11 ng/l (Floyd's level).
Invite the Prosecutor and any members of the jury to take enough Fentanyl to get to 11 ng/l, since OBVIOUSLY it was Chauvin's intention to kill Floyd with Knee on Neck, so OBVIOUSLY the amount of fentanyl in his system had nothing to do with it.
Obviously, the MD would refuse, and explain that giving anybody enough fentanyl to reach 11 ng/l is enough to kill them, and he'd lose his license.
Surprisingly enough, the slam dunk is gonna be the expert witness who testifies that the knee to the neck maneuver was in fact a part of training and they will go on to explain why. Then they bring on a MD to then explain why it didn't kill him and why it wouldn't.
I know we all are pretty stilted here concerning the fairness of the judicial system but there isn't anyway around this fact. A jury will be instructed that making a decision on whether the knee to the neck is a legitimate method is not for them to decide. They will not be able to show mens rea.
Now they could pull in all sorts of nonsense like racist comments and potential indications that although the knee to the neck was part of training Chauvin knew it could kill (it can't btw and I'm fuckin' tired of people saying dumb shit like "Look, there is no reason to lean on a mans neck for 9 mins". Right and he didn't. His knee is just above his neck and that can be seen in the video).
Fuck, I would go a step further and have a demo performed. Hell, I’d even volunteer to be the Floyd stand-in and exceed the time experienced, sans fentanyl of course.