They knew the rules and refused to move back when told to by the officials, so it was always on the cards. It's laughable how much importance is now put on the Haka, if you watch clips of it from the 70s it is hilarious. I don't mind them doing it tbh, but I don't see why the opposing team should be forced to do anything other than stay in their own half, if they want to go into a huddle and ignore it, that's their call, or even continue warming up like Campese did in 1991.