Hitting people and walls

[Hard Boiled]

If you have a room, or even an arrangement of walls, and the corner is exposed, you can manage to still hit someone exposed on the other side, but you cannot pick up items from the other side. It's odd, because, you should not be able to hit someone when there is no space for a fist of item to get through, and you can, but items on the other side cannot pass through? I'm not sure how to post pictures here, but I hope this works.