Usually they put loads of sugar in flavoured spirits.
The thing about the liver - nmr I think they told you a slightly confusing version. I have to say I only recently fully understood it after going on a DAFNE course. Basically when you get drunk, the liver's priority is to deal with the alcohol. So it stops doing lots of its normal stuff. One of the things it normally does is convert stored sugars and put them in your bloodstream to keep you going (that's why even if you don't eat anything, you still need to inject a bit to handle that sugar your liver is spewing out).
If you are drunk the liver doesn't spew out as much of the stored sugar, because it's busy handling the alcohol. So if you have injected insulin in your system it will continue doing its job but the liver's stopped doing what it normally does. Result: not enough sugar to match the insulin = hypo.
So one shot of flavoured vodka - probably your blood sugar will go too high. Your liver's probably working like normal.
Lots of shots of flavoured vodka - the liver slows down and puts less sugar in your blood, but you've got loads of sugar from the flavoured vodka so you don't go hypo (you may even find you don't go that high)
Some glasses of dry wine - the liver slows down and there's no extra sugar so you go hypo, as you did, nmr.
Of course in practice it is REALLY hard to get that balance. And everyone's different. I'm a bit more of a boozer than nmr and 2 glasses of wine would not send me hypo, but brandies will send me hypo for the rest of the following day.
The best thing is to experiment till you find out what works. Well, some would say the best thing is not to drink, but I would not say that. Don't forget:
Unflavoured vodka, gin etc= no extra sugar
Dry wine = no extra sugar
Sweet wine = extra sugar
Beer or cider = extra sugar (it doesn't taste sweet but a pint of beer is about 10g carbs)
The alcohol in all these things will have some effect on your liver and how much sugar it converts from storage.