I doubt there's a distinct connection between alcohol itself and your result, except possibly for the dehydration.
Like the PP who has had both ways, I normally weigh more after drinking than before.
Some people have found that an occasional high-intake day has helped them get back to losing when they're struggling to - people who aren't eating enough day to day. This could be what you've done, but you'd really need to experiment and test it a few times, and keep your body starving to do it, so it's not something I'd advocate trying again.
Just try not to be disappointed if that weight shows up again in a day or two, and if it stays away, be happy about it. It's not worth trying to replicate - any number of factors could have been in play.