I think you mean it shouldn't happen undetected... these kinds of mistakes can and do happen. Everything from human error (oops, Billy put baking powder in the

I think you mean it shouldn't happen undetected... these kinds of mistakes can and do happen. Everything from human error (oops, Billy put baking powder in the baking soda tank) to equipment error (the tank valve stuck open, adding 10X more of ingredient X than expected)