Racing isn't exactly "every other business". In a competitive business with multiple trade secrets once a key person let's it be known they are going to work for the enemy you just cannot keep them around. And they shouldn't want to stay. If John goes out in the first round at the last two races with Jimmy tuning, it'll look like he tanked. Jimmy should be glad John let him walk after the cat was out of the bag. The Don would have done the same thing...it fact he has.