Visible crew/equipment: Number 6 enters the room with the huge globe, and we "follow" him around a map table. As the camera passes the table, it films its own shadow falling across the map.
Visible crew/equipment: When Number 48 jumps from the council table, there's a clear shadow on the left of someone holding up a still camera.
Answer: It's even more obvious than you think, you know who number 1 is in the very first episode. When 2 replies to the question "who is #1?" Change the way he answers from you are number one (in the monotone or accented answer to, "You are, number 6. The comma gives you the answer. #6 is #1. It's the tone of the answer.