A German WW-II submarine officer looks through the periscope at night for enemy battleships. The crew of a nearby Allied vessel believes they’re in safe waters. The ship’s decks are well lit. The German submarine officer sees the Allied ship’s lights through the periscope, reports to his commander who fires a torpedo. The torpedo makes a direct hit.
Meanwhile, the captain of the Allied battleship is deep in his quarters and muses, what terrible luck, we’ve hit an iceberg. He notes with bitter irony that he was just getting some ice for a shot of whiskey at the very moment that his ship struck (what he supposed was) an iceberg.
For the Allied captain, the ice cubes and the impact of the wrongly imagined iceberg were acausally connected. He radios his base commander and tells the sad story. The radio transmission is overheard by the German submarine officers. They laugh. They know it’s no iceberg.