The tell-tale signs of the type of trauma that is done to the throat in the cases where the knee to the neck does cause death are absent in Floyd's case, but so are the tell-tale signs of a drug overdose, as far as exterior signs. His lungs were two pounds heavier than average due to adema almost definitely caused by the fentanyl. The most likely meaning is that he died from the drugs with an atypical presentation of fentanyl overdose, so even a cop trained to look for the usual signs would have missed it.
Eighth circuit court of appeals already ruled that knee to neck is not excessive force, and is justified for cops to use in the performance of their duties, and said cops can't be sued for using it even if it results in death. In the case they ruled on, the death of the detainee was proved to have been a direct result of the technique, and the officer involved used it for around 16 minutes.
This is all political theater. The media can't control the evidence presented in actual court like they can in the court of public opinion. It's unfortunate that Floyd died, and Chauvin may actually be a dirty cop, but those two things do not make him guilty of murder or manslaughter.