When Rob begins to climb back down into the elevator through the trap door, his back is to the side of the elevator where the door would be located. The shot then cuts to the inside of the elevator and Rob is entering with his left-side now to the elevator door. His back is to a side wall.
When Rob is atop the broken elevator, he shouts "Hello, is anybody there?" Inside the elevator, Laura and Lyle (Don Rickles) respond as if it's a rescuer shouting to them and rush toward the elevator doors. At this point, the camera pans right and reveals that the elevator "juts out" to the right at an angle indicating that this elevator is "L" shaped. Elevators are "cube" shaped and do not angle off in extra directions.