My father was a Marine lieutenant and interpreter of Japanese in the Pacific campaign. One of his stories about the experience was about the senior Japanese interpreter, a captain, and a good guy, who enjoyed telling the following story on himself:
The captain was called in to listen to an enemy radio intercept and translate it. He dutifully did this, struggling a bit, but handing in his written summary of what the enemy conversation was about.
It later turned out that the enemy radio intercept was actually an intercept of some of our side’s Navajo code talkers...