Question for our Epic'd Sk's

[Omarley]

So last night after a few nights of Exping in the hole, a group of friends finally got the Ratman Guard to spawn. After killing him, he did not have the Dusty Tome. From all walk-throughs and everything i have read about the SK Epic Quest quest online, it says this should be a 100% drop. Is that the case? Did any of you not get him to drop the book on one kill? I figured i would ask those who have done it, before i make an ass of myself in Bug Reports!
Thanks in Advance!