A filmed landing would leave a sprawling human trail
A soundstage theory has to explain more than who operated a camera. The Apollo missions depended on a chain of work: spacecraft design and construction, launch operations, mission control, radio communications, tracking stations, and the return and handling of lunar material. Those jobs were spread across organizations and locations. A fabricated landing would require the relevant participants—or enough people at each handoff—to produce a consistent false account and keep it intact over time.
That does not mean every engineer or technician would have to know about a conspiracy. Large projects are divided into specialized tasks, and many workers see only their part. But division of labor cuts both ways: a staged mission would still need convincing records, communications, hardware, and samples to pass through many separate hands without creating a credible leak or contradiction.
The signal was not confined to NASA
Apollo radio transmissions could be received and tracked beyond mission control. Observers outside the United States, including the Soviet Union, could monitor the missions; during the Cold War, the USSR had a strong reason to challenge a false American claim if it could demonstrate one. Independent tracking would not by itself prove every detail of a landing, but it makes the idea of a production hidden entirely inside a studio harder to sustain.
The practical problem is therefore larger than keeping a secret among employees. A hoax would have to account for what people outside the supposed filming operation could observe, as well as for the many physical and documentary traces created by a real spaceflight. Each additional piece of the story would need its own cover story, carried consistently across decades.
That is the burden behind the secrecy argument: a studio set could imitate a scene, but the theory must also explain how an enormous, distributed operation left no decisive trail of fabrication.
