Without reading the threads and just taking your description at face value, I disagree with them. I do agree with their explanation that lack of an atmosphere explains the observation adequately. I don't know much about sand, but it seems unlikely that one couldn't create relatively dust-free sand. Again, though, I'm ignorant about the physical properties of sand beyond what one would learn from the occasional excursion to the beach.

That's not to say that I consider it likely that this was dust-free sand. That is, I don't consider this evidence that the moon-landing was a hoax.