Deter middle managers from what? Implementing shady business practices that skirt the edge of legality? That's day-to-day business, the only way to avoid that would be to quit. Sure, no one would commit this exact offense again, but (a) the practice will (would, if any conviction actually happens, big if) be changed just enough to make it legally ambiguous again, and (b) the law would probably be changed to make it legal.