lol axxo they modified something that allows them to show 2nd shot in our screen, i have no idea what that is, if i knew i would talk about it
i am not sure if they modified it via weapon.dat, but i've seen aurora users actually firing like that, so it means it's something included in aurora files
there's only one way to make this "double C" work, and that is when you fire the 2nd shot, you need to hold W and your fire button for longer, so that anim will play in opponent's screen
in all the videos i listed, the players that did it have no actual delay while firing, which means they use custom vcmp stuff to make them get advantage
editing weapon.dat is actually not really the thing, because as you said, if they did this then most likely ghost shots would appear in their screen and they would not hit opponent with the 2nd shot, instead they'd get shot by the opponent
anyhow this is cheating assured.. see all the videos i linked above, it's no way anyone could deny this isn't cheating on such clear proof, and as i said most players would rush to say it isn't hack, but that is cuz of lack of knowledge about vcmp