All he had to do was wear civvies. He chose not to. He also chose to take the oath of a commissioned officer. He chose to disregard THAT oath. When you're in the service, you obey lawful orders.
Personally, I think they should release him from duty. Then he can do what he wants, with any parish that wants him. If he wants to do it in a uniform, let him refound the Templars.