I report this in case it has something to do with the situation I was in.

My friend and I were filling up our car at Severograd gas station with a canteen at night. I was going to check how much fuel we got by getting into the driver seat.
As soon as the animation started my game crashed. After restarting the game and loading into the server I spawned on top of the car of 2 strangers parked in a city and got shoot.
My friend couldn't hear the shots so I must also have spawned in another city. Also, it looked like one of the guys also had a relog.
I could not reproduce the bug. Maybe when 2 players enter a cars driver seat or general a car at the exact same time it can happen? Just a guess.
Also, it was not the same car as ours.
If this is somehow reproducible it would be a game braking exploit.