I was playing on an official server and was knocked unconscious by zombies. While I was unconscious (not dead!) my connection to the server was lost. When I tried to log back in, I got an error code saying another user with the same UID was already in the server. I waited a few minutes and when I was able to log back in, I spawned as a new character. I was pretty far in the game, so having to start all over when I didn't even die was pretty frustrating.