Macron is just using theatrics as a political ploy to play to the home crowd. The fallout would seem to be that Macron is the one lying. If he really has a problem he can send some members from the action branch of the Direction générale de la sécurité extérieure to plant some limpet mines on a Australian war ship in Sydney Harbour and perhaps kill some people in the process. Something they've done previously when upset (Rainbow Warrior in Aukland Harbour).