In the book Starship Troopers, Colonel Nielssen is discussing the chain of command with Juan Rico and two other cadets:
If you go back to the Second Global War, you can find a case in which a naval junior officer took command of a naval ship and not only fought it but sent signals as if he was an admiral. He was vindicated even though there were officers senior to him in the line of command who were not even wounded. Special circumstances -- a breakdown in communications.
Is Heinlein referring to a real incident and, if so, can you identify the ship and battle where it took place?