Is Hard alcohol REALLY ok when you are on a low carb diet?

I have a friend who is on a low carb diet. She insists that Captain Morgan has no carbs in it and it's just empty calories so it's ok to drink on her diet. She can (and will) drink her weight of Captain Morgan if you let her. Ya - it says 0 carbs on the label. But from a health standpoint doesn't any hard alcohol have sugars in it? I thought that when you eat carbs, your body breaks them down into sugars and whatever you don't burn off turns into fat. So when you eat sugar aren't you just saving your body the time of breaking it down and just eating it directly? Hence why diabetics should avoid alcohol and why on the Atkins diet they have you completely avoid it as well. So how in the world can drinking an excess of hard alcohol be good for your low carb diet?