In the original version, people could be "Downed" as in Left 4 Dead where they could not move and would continuously lose health (as well as zombies attacking them) until they died or were saved by somebody walking over to them and clicking them where they were recovered.
Since v10 (and v11 too I guess), this feature is broken and people will be stuck "dead" and respawn leaving a clone of themselves behind if they die with "Downed" enabled.