 Reportedly, there are two versions with different endings.  One version ends  with a missile being fired and a torpedo being released from the sub seconds  before.  In another version the sub is destroyed, and later that evening the  German commodore is found aiming a .45 at the nose cone of a live missile.   The captain asks why, the commodore gives some reply and pulls the trigger.   Mr. Munceford is blown over the side, but survives.