If two hunters or recreational shooters didn't know the other person was there?
Earlier, I mentioned the 4 absolute rules of firearms handling. This is covered in Rule 4 - Know your target AND what is behind the target. Unlike in the movies, real bullets don't just stop when they hit flesh. More often than not, they exit the other side and can continue to do damage until they are totally spent. That is why you must make absolutely certain you understand what could potentially get hit after you pull the trigger.