For the sake of argument, suppose that we know that some action leads to a death 0.0001% of the time. In such a situation, murder would be an inappropriate charge, because a person shouldn't reasonably be expected to have known that their actions would lead to that death. For example, imagine that someone has a stress-induced heart attack as a consequence of a police encounter. Is that murder? Obviously not, even though in this example the police's existence was a necessary condition behind the cortisol spike which lead to that heart attack.
At the other end of the spectrum, if you shoot someone intentionally, you know that there's a ~50% chance that they'll die from that, so your intention to kill is implied from the act and murder is therefore appropriate.
I don't believe that 0.0001% is the correct figure for what Chauvin did to Floyd, it's certainly higher, but it's not an irrelevant question.
If Chauvin believed he was following MPD procedure (which he wasn't exactly, but it was fairly close to training materials), and that procedure leads to death only a very small % of the time, there's a plausible case for a lesser manslaughter charge there, or even no criminal charge at all in the general case where procedure was followed closely (which it wasn't here) and that procedure is generally safe.