In the scene where Sarek visits Kirk's apartment, the camera pans the room. In an alcove, are two sets of dueling pistols hanging on the wall. The top two are pointed at an angle, with the barrels facing up and in and the bottom two are pointed down and barrels in. After some dialogue between Sarek and Kirk, the camera pans around the room again. Lo and behold, the bottom pair of pistols is now pointed up and in.