*shakes fist at sky* Whyyyyyyy?
Sorry. Just one of those bugs, I guess. Should've been fixed.

If you could walk through what you did during the quest for me, so that I know where to look.
- Did you talk to Maeron? (there should be a journal entry)
- Did you talk to and accept Marcus Aratorius' offer? (another journal entry)
- Did you talk to and accept Lucius Decimus' offer? (ditto)
- Kill any wolves? Kill the wolf outside the cave?
- Did you lie about anything to Noam?
From what you've said, you selected the diplomatic route with Noam, and got the mudcrab meat. That presumably means you got this journal entry:
I have retrieved enough mudcrab meat to satisfy Noam. I should return to him.
And this journal entry:
I gave the meat to Noam, who seemed relatively pleased for somebody of his temperment. With the danger of wolf attacks stopped, I should talk to Murg.
Now I'm a bit confused after this. You said you were at stage 100, and yet you had tried to talk to Murg and had no options? Stage 100 should only show up after talking to Murg and getting this dialogue:
You took care of those wolves? No more sheep is gonna get eaten? Thanks. You good friend of Murg. Just wish I had somethin' to give you in return.
Presumably if you can't get a response out of Murg at this point, you should still be at stage 70. *shrug*
If you can elaborate a bit, that would help. This particular bug seems to be pretty obscure - you're not the first who's had it, and I can't seem to track it down. Hopefully it can be caught this time.