This sort of thing has been happening since before WW1:
In 1904, an A Class submarine commanded by Reginald Bacon did exactly this. Umpires of a naval exercise that year determined that Bacon's 1st Flotilla had sunk two battleships (they claimed they had sunk more). CIC of the Home Fleet, Sir Arthur Kynvet Wilson (who had been a real enemy of submarine development) was naturally infuriated by this.
When, during the exercise, a submarine signalled his ship with
'Respectfully submit have torpedoed you. Respectfully submit you are sunk. Respectfully submit you are out of the exercise.' apparently Kynvet Wilson grabbed the semaphore flags from his signaller and sent
'You be damned' with them personally.

Chock