It was probably a hacker, happened to a friend of mine once, right in front of my eyes(body slowly sinking as soon as he died, killed by pissed off hacker) or it could have been a bug, not sure. But once you feel like playing DayZ again, play on a less populated server(like 20 players) so chances of meeting a scripter is less common and play with a friend next time, it makes the hard part of DayZ much more bearable. Good luck.