No special explanation needed - it happened 2 or 3 times to me: I was just minding my own business ingame, and all of a sudden "You are dead", no shooting or hitting sounds, my friend confirmed me that there weren't any other players nearby, light green hydrated, energized and healthy. Last time Happened in the upper room in the barracks at North West Airfield. Additionaly all the items and corpse disappeared.