I don't know if this bug still exists for minecraft 1.9.1 but it is very strange.

It was on a multiplayer server. When someone dies, he will become invisible for the other players. It was on a map. When the player dies, he respawn in 2000 100 2000 and is teleported 1000 blocks away. I don't know if the bug is caused by this but it is the best hypothesis. To fix it, we had to disconnect and connect to the server after every death

The map used:
http://time4play.net/evowar/