You say that as if it was established fact (that Floyd died because of fentanyl and heart disease). Its an opinion. The Medical Examiner ruled his death a homicide. The ME acknowledged those conditions. Dr Fowler, a South African immigrant, was a witness for the defence, and was expressing his opinion, rather than medical determinations. He was not part of the autopsy. Under examination, he admitted that even someone deprived of oxygen ultimately dies of an arrhythmia. He also conceded that Floyd should have received immediate medical attention when he went into cardiac arrest. Ultimately, the jury rejected Fowler's arguments, and Chauvin was convicted of murder and manslaughter. His statements during the trial drew ire from fellow medical professionals. He was a retired ME from Maryland. As a result of his statements, where he has been accused of malpractice, reviews were carried out into various deaths in police custody, where he brought forth similar "undetermined" causes of death. https://www.cbsnews.com/baltimore/news/autopsies-of-100-marylanders-who-died-in-police-custody-under-review-after-former-medical-examiner-testified-in-george-floyd-case/ https://www.cbsnews.com/baltimore/news/maryland-medical-examiner-david-fowler/ https://therealnews.com/fowler-medical-examiner-botched-cases-that-still-haunt-us https://www.nbcwashington.com/news/local/autopsies-misclassified-deaths-in-police-custody-that-were-homicides-maryland-officials-say/3915122/ He may well face prosecution. There would be limited point in censure, given he is retired, and likely has let his licence expire. However, it might affect whether he is called as an Expert Witness. I was once called as an Expert Witness for both the Prosecution and the Defence in a UK case. It was interesting. For the prosecution, I was supposed to provide an alternate opinion to the Crown about the ability to make a noxious substance. For the Defence I was asked to describe how such an effort would lead to a contaminated noxious substance, affecting overall toxicity, and that production of a noxious substance was purely by accident. In the end, the defendant copped a plea, and I breathed a sigh of relief.