Let's say they still could not authenticate the orders and Captain Ramsey was the one who did not want to fire the missiles but the XO did. Could the XO still relieve him from his duties and not be in trouble at the hearing.
I've often had a problem because he is a captain of the submarine and XO is just a Lt. Commander. I guess full Commander or Lt. Commander he still had a duty perform and was obligated to do so.
The XO relieved the captain from duty because the captain tried to replace the XO for not going along with the launch. COB said so as well when the XO thanked him. COB said he didn't want to support him but the captain just can't replace the XO. Had the situation been reversed and the captain refused to go along with the launch the XO would not have been able to relieve him because he wouldn't have the support of the crew.
shareThe key factor is that release of nuclear weapons requires concurrence of the two officers. If they are not in agreement, it really doesn't matter which officer opposes the launch, and it really doesn't matter which officer is right (meaning is correctly assessing the validity of the orders.)
So, the answer to your question is definitively "No." The XO would have zero grounds to relieve the captain on the basis of the captain deciding not to launch, even if there were perfectly valid orders to launch. The fact that there is disagreement means that the required elements to launch are not in place, by definition. Attempting to rectify that situation by changing personnel is a circumvention of the most important safety measure in the system.
That's how I interpret it, anyway.
"Morbius, something is approaching from the southwest. It is now quite close."