I was able to find the ale all the times I tried. I believe it's in the uppermost center room in the castle, on a table.
The one I wonder about is the drunk robber you meet in front of Blue Boar (forget his name now). If you go around him, you meet his wife/girlfriend, who asks if you've seen him. If you do encounter him, you don't meet her. Seems like there's something missing there.
