I'm glad you are a better official than a mathematician! 
25% reversal of 2 stoppages per game = .5 reversals per game, or one every two games.
5% of reversals are incorrect: .025 per game (5% of .5), or 1 every 40 games.
not sure about a better official but looks like I flunked math, that's for sure - BUT, "math IR" fixed my mistake!
