restricted Mr. Floyd’s breathing by flattening his rib cage against the pavement - a knee on a person's shoulders doesn't necessarily flatten the ribcage enough to cause death by lack of oxygen.
We still don't know what caused George Floyd's death. This needs to be established in a court of law.
The prosecution will no doubt call experts to the stand who will claim Floyd was killed by Chauvin; the defense will call experts who will claim that the amount of drugs in Floyd's system is reasonable doubt re allegations of murder; the defense will also claim that available evidence doesn't support the murder claim beyond reasonable doubt.
The pro-BLM MSM have already declared Chauvin guilty of murder before the trial, lol.