Could've been staged by the Russians, or the Ukrainians could have used small drones to make their radar signature basically undetectable. Of course the corrolary of that is that they can't pack more than like a grenade at most. It's meant as psychological warfare; to show that Moscow isn't immune. They can't do real damage.
Isn’t it possible for them to take it apart and assemble it in some rural area. It doesnt necessarily have to fly all the way from Ukraine to Moscow. As for the “could’ve been staged,” we heard that for the NPP and then Telegraph many months later said the Ukrainians attacked it. Same thing with the kremlin attack when western officials poured cold water on it. Then you have to ask yourself the question. Why would the Russians need to stage anything? We just had the Belgorod raid not that long ago.