Exp patch 1.0.150.192 (from 1/16/19)

If you kill and gut a large animal (a buck, for example), and drop an pre-existing item from your inventory onto the pile of meat/bones/fat (in other words, something other than what came from the animal), three icons appear of the dropped item.

Note: the items themselves are not duplicated, only the icons. Any of them can be picked up, but two of the icons remain. If you walk a few feet away and come back, the duplicate icons are no longer there.