Thank God there are multiple real world examples of officers getting the order to fire a nuke and disobeying it.
> Unlike the other submarines in the flotilla, three officers on board B-59 had to agree unanimously to authorize a nuclear launch: Captain Savitsky, the political officer Ivan Semonovich Maslennikov, and the chief of staff of the flotilla (and executive officer of B-59) Arkhipov.
Arkhipov had authority to veto the order. What's more, the captain was assuming war had begun and had no order from above to attack.