OK hope your are saving so you can go back if this don't work.
Has the thug ever shown up? You said you were caught up with all of Jester's tasks, right? And talked to Harold about the bandits? And Bernie and Logan? I would try to go all the way to 100 and check for the thug in a couple days. And do it before Night (20:00) to see if that works.
I know I have seen him in the tavern early as 14:00 when it opens, and I am pretty confident I got the clash once at 19:00. I know Night is 20:00 but the alternative is Daylight, evening is vaguer, it is 18:00 or 19:00 for some events.
Anyway I save and reload all the time checking things, may not be the way you want to play. That is all I can think of to try and help.