Like 5 times in a row now i've gotten sniped, only in the thorax, armor being ignored, through walls, ONLY after picking up rare items.
Found a teapot, USB stick and a bunch of euros in a safe, door to the room and hall closed, window far out of sight, immediately shot from nothing.
Found a gas analyzer, pressure gauge and four guns. Shot by a SVDS sticking outside the red gate leading outside the map while trying to extract from admin gate.
Just now, found i kid you not 12 bodies at RUAF, picked up 5 guns, a full grizzly and a bunch of armor, shot by someone just on the other side of the southern wall, again outside the map.
All were when i was scavving, all killed by scavs.
They can tell what's in your inventory and whether you recently picked up a rare item, me thinks. Or i'm just getting killed at the unluckiest of times by MLG ai scavs.