The flag moves when he is holding onto the flagpole and shaking it slightly. You can see from the way the fabric moves that there’s no air, if you think about it.
The reason we never went back is that there was no reason to. And it was very expensive to go there in the first place, setting up a moon base would have been a million times more expensive.
We only went to stick one on the Ruskies. Point proven, end of moon programme. Simple, innit. Like your Missus 🙂