I remember reading a story in "Inside the Soviet Army" back in 1985. During WWII, the Soviets had developed a new secret weapon, I think it eventually became "Stalin's Organ", a multiple launch rocket artillery system. When it came time to demonstrate the weapon to Stalin, the wrong ammunition was delivered. The rockets were the same diameter as a common artillery shell, and the supply man didn't know about the rockets.

In normal circumstances, Stalin probably would've had someone executed for that mistake. Instead, he ordered that the artillery rockets be designated with a different diameter to reduce confusion in the field. In the best tradition of the blind squirrel sometimes finding an acorn, Stalin made a reasonable decision to reduce operational errors.

That didn't happen very often, though.