Excuse my bad English, but I hope you can find the meaning I wanted to write:
It's a bug, it also happens in vanilla (so its BIS fault). (Longer arma/ofp users know how it is with netcode and where calculations are calculated (shooting, movement,...). So it is not surprising.)
It usually happens when a player leaves the vehicle. He normally runs out and he normally moves, but some players see him still in the vehicle. And so he can kill you the "ghost" without seeing him. But this that it happens to somebody in the free space, I see it on the first time.
But it is highly probable that it has the same denominator. I know it sometimes did not help nor reconnect when I saw it on the Liberation server.
And It happened once in coop action too approx 2 months ago, people never saw me outside of the car, but they saw me several times in every vehicle where I was in sometimes. (For them I was 3 times at the end of the mission in 3 different vehicles). This is the photo of the mission, I'm on it twice: https://scontent.fprg2-1.fna.fbcdn.net/v/t31.0-8/19221455_1741454409216646_2990138669443970362_o.jpg?oh=a732f2cf7503872bd3a2d856f276caef&oe=5A255386
But on this event I saw it in pvp/tvt for the first time when it happened to one of us as well (I think hunt, on the ocap he was still in the car).
The problem is that the player himself does not have the chance to find out that he is in this bug for any other player. he doesn't necessarily have to be buged for all players! (I checked this out last week)
I have a couple of friends in BIS, I'll try to find out if they know about this bug, because for pvp/tvt it's a pretty significant problem, but I can't promise anything.
The question is, how to proceed if re-connection does not help? Disconnect completely from mission?
Otherwise it would be considered a violation of the rule 0.4.1. "Using of game bugs" (?).
Arma is not a perfect game, but it's a perfect random bug generator.