Philip Vian risked his orders to stay with Bismarck

When did a Royal Navy destroyer commander disobey wartime orders and get away with it?

Philip Vian left a convoy to chase Bismarck, then justified the risk by maintaining contact and contributing decisively to the battle.

Philip Vian left his convoy duties to pursue Bismarck, risking an order to return before his destroyers could join the action. Reaching the battleship made that initiative useful: the destroyers maintained contact through the night and repeatedly attacked in formation. Keeping Bismarck under observation prevented her from escaping unnoticed. Vian's favourable reception depended on that successful intervention, which justified his departure from convoy duty after the event.