had this happen the other day (been a long time since i've seen it) and the only thing i can think of is that its tied into being idle too long and somehow your game desyncs a bit. I was on a team, had company come over so i pulled out my calc, clicked use on the rax and pulled up my vehicle build screen, afk for next 45 mins or so, map changes, i go back to play it and ragdolls are doing the humpty hump on the floor.
It's happened to me a few times, usually when I alt-tab during a game and go look at stuff on the internet/msn and then alt-tab back in. Yeah reviving is impossible then. A question regarding ragdolls: Why is it that the ragdolls are inconsistent between all clients? I've seen people run to nowhere and revive me even though my body is a few meters away.
Because the ragdoll physics are calculated on each client individually. Having it calculated server-side would put a gigantic (and unnecessary) strain on the server. Check the posts above for this exact discussion lol :p