Art defacement: This was a bug in the game and not caused by what I thought it was at the time. It happened because Meng Berdakas, Dwarven Master Chef made a masterful roast entirely of liquid ingredients (booze and maybe milk), and the "roast" decomposed into a puddle of booze and maybe milk, shortly after its completion. This was very mysterious at the time and I did not know about the DF bug tracker.
So, just to clarify, there was in fact no Urist McGuilty. I never knew this until long after the end of Nutscaves, though.