That’s such a fun story.
Drinking Dwarfs spill beer on the floor.
Liquid behavior on floors is modelled.
Cats might walk through the puddles.
Cats clean their paws by licking them.
Animals inherent the ability to get drunk from some class.
QED: cats get drunk.
And, because every drink of alcohol was assumed to be one cup worth in some throwaway bit of code, and cats are small, they got massive alcohol poisoning and almost instantly puked themselves to death.
So, bug. The observed behavior was cat corpses and cat vomit accumulating in bars. The expected behavior was… not. Eventually Tarn managed to figure it out, and it was fixed by better modeling of the volume of just a layer of liquid on a body part. You also can’t suck stuff off yourself to quench thirst in adventure mode anymore.