I think there are two other things that need pointing out as reasons why being on a VLCD like Exante can cause blackouts and potential fatality:
1) Whenever someone doesn't eat, they are likely to get drunk quicker and possibly pass out. That's because food in the stomach helps to sponge up alcohol and it's released a lot more slowly into the bloodstream. If you're just living on shakes and maybe a solid bar, you're going to be feeling the effects of alcohol a lot more quickly than someone who has eaten a meal before going out!
2) Our own fat absorbs alcohol, so overweight people tend to need to drink more alcohol to get drunk. If you're not drinking very much (if ever) and rapidly losing weight, you're not going to be accustomed to the effects alcohol will have when you're at your new weight as your old weight.
Personally, I do not plan to drink on this diet anyway, just because I'm not a massive fan of drinking (I tend to be a smoker, not a drinker) but I think as well as above, people should be mindful of these two considerations.