One of the mythos cards in the game says that the investigator is out of ammo and that she needs to discard her weapon. Would you interpret this as the card should be removed from the game as oppossed to the cards that says the investigator needs to drop the item, ie. in the current room.
I would have said remove the card if it wasn't for that the investigators have an action called "discard" where they actually drop the items in the current room.