As far as I know, the solar wind is so weak that it requires solar sails of hundreds of metres square to catch enough of it to accelerate a tiny spacecraft at a moderate rate. If the wind was enough to shake that flag then there would be dust flying all over the Moon's surface. Did you ever notice any on the films? The dust is extremely fine, you know.If this is true we can factor out solar wind.
There is just not enough information to determine how long a sheet of unknown material and unknown construction, on a light, whippy support, could carry on shaking if it were nudged. The movie is not long enough to reveal the real situation but Occam's Razor, when applied to all of this nonsense tells us that it really was waving and it really was on the surface of the Moon.
I have to question the motives and the sense of people who are still looking for evidence that it never happened. There must be fairies at the bottom of their gardens.