What's the worst thing that can happen to an alcoholic who has 'a slip' with a drink or two? Gets drunk? Fight with the girl? Jail?
Nope. The worst consequence for a real alkie who has 'a slip' is nothing. Nothing happens and you get away with it. And then somewhere, someday, all hell breaks loose. You never recover because in the back of your mind you have a reservation that you can somehow drink safely.