in rare cases, even the "flesh was cut!" sound plays but no damage is dealt
That shouldn't happen. The EV_whatever (event that makes the "flesh was cut" sound) is sent from the server, and unless the server's bugged it shouldn't happen. It's like getting a dretch to bite a teammate, which won't happen afaik because of the conditions that must be confirmed for the autobite to activate through.
Another example is tesla generators. They only hit if they can, and hit dead-on.
However having a turret kill a teammate is a different story.
Anyway, have you ever seen my video "Demo vs Live" clip(s)? It really shows the difference. It's in two parts though, so you have to watch them seperatly, I was going to use them as evidence for my "demo lag" article that no one gave a fk about.
Gee I wonder how I brought that up, what a silly impulsive mind I have there.
Anyway my point is that it is possible to "strike dead on and miss" but you shouldn't get a confirmed hit error sound. I have many times, had a swiping sound occur more than 3 times, but that only happens if I clip into the enemy and get those prediction errors.