is the most likely explanation that you could think of that fits the available evidence. But it could still not be the right one; you may have completely missed the true explanation.
Because Scott blocks our view at the critical moment, we simply don't know (without further analysis) whether he touched the flag. Although at first glance it looks as though Scott was too far in front of the flag to have touched it, this is not necessarily so. The TV camera had a zoom lens set at wide angle, and wide angle lenses tend to exaggerate depth, sometimes quite considerably. A photometric analysis of the video and the still pictures taken from the side at the same time is inconclusive; it doesn't show that he must have hit it, nor does it show that he could not have hit it.
Here we come to a critical part of the analysis. Whatever conditions were in effect at the moment the flag began to move were most likely in effect through the entire scene. That is, if air was present on the "soundstage" at the moment Scott moved the flag, it was almost certainly also present a minute earlier and a minute later -- unless the "soundstage" was rapidly pumped to a vacuum or vented to the atmosphere. That raises the question: what happens at the other times an astronaut walks closely by the flag? At one point another astronaut does indeed walk closely by the flag, this time behind it so we can see how close he came. The flag does not move at all. Now if the hypothesis is that the "soundstage" had air, shouldn't the flag have moved every time that an astronaut walked closely by? The fact that the flag doesn't move these other times allows us to rule out the HB's theory that an air current was responsible the one time it did move. Only one candidate is left, so we can conclude that the flag moved most likely because Scott brushed it as he passed, probably with his left arm.
The HB make many claims like this one. They take one picture, one brief excerpt of video, or one line of dialogue and claim that it alone proves the entire Apollo program was fraudulent.
Despite the false dichotomy implicit in their negative argumentation, HBs readily concede that hoaxing the moon landings would be by far the largest, most elaborate and the most successful hoax in human history. Yet the notion that a hoax so huge could remain totally airtight for four decades is simply beyond credulity. Nothing else even comes close. Known conspiracies and hoaxes on a far smaller scale have repeatedly fallen apart in far less than 40 years. The Watergate break-in and related Presidential wrongdoing was revealed within a year of its occurrence. President Nixon was forced to resign after only about two years. The Iran-Contra scandal came to light only about a year after the fact. Some Apollo HBs repeatedly stress the huge scale of the alleged Apollo hoax to stroke their own egos at having "cracked" something so important without realizing that they are merely underscoring its implausibility.
Space telecommunications was one of the things that inspired me to get into ham radio (I was first licensed in 1971), earn two college degrees in electrical engineering (Cornell University in 1978 and Carnegie Mellon University in 1979), and ultimately a rewarding career in the communications and computer field.
To show the scope of the communication systems used by Apollo (and how far we've already come since those days) I'm putting together some link budgets for a few Apollo missions. A "link budget" is an accounting, generally done on a spreadsheet, of the signal and noise powers on a communications link. It starts with the radio frequency (RF) power generated at the transmitter and computes how much of it reaches the receiver input over the specified distance with the particular transmission lines and antennas at each end.
The link budget separately computes the equivalent noise level at the receiver input from a variety of sources including the receiving equipment, the antenna, various celestial sources and even the cosmic background from the Big Bang. It then compares the two to produce t