The sugar and carbs in alcholic drinks will spike insulin. However, as you proposed, we are only talking about "pure" alcohol.
I would be more concerned about alcohol lowering blood glucose levels -- especially for diabetics and those of us paleos that walk the VLC / LC line. It only happened to me once, but I ended a randomly VLC/high-protein+fat day with a bottle of wine. I won't say I almost died, but I certainly thought I might: extremely dizzy, nauseated, blurry vision, spots in vision, light headed ... and not in the fun, booze-type way.
From DOES SUGAR IN ALCOHOL SPIKE INSULIN?:
Symptoms of hypoglycemia include dizziness, disorientation and sleepiness; however, these can also be side effects of drinking too much alcohol. This is why it's so important to actually check your glucose level, rather than rely on how you feel to tell whether your glucose levels are fine. Other symptoms include seizures, double or blurred vision, loss of consciousness, anxiety, sweating, hunger, tremor and heart palpitations. You may also experience confusion, or the inability to complete tasks that you would normally do.
I'm not diabetic, so this event really left an impression on me. I still enjoy a bottle of wine (ahem or two) every so often, but I make sure my diet that day gave me a good base to otherwise punish my body. Having a hypoglycemic event was definitely not a good time.