That's an amazing streak. 81. Wow. I knew they could pop multiples but that's insane.
Funny thing is that I was in CoM yesterday for that ghost you mentioned (part of the Shaman epic.) So we pulled (accidentally) the black reaver at the end of the first hallway, and he died, and immediately, the ghost popped. Woohoo. That was a lot easier than I was expecting.
Now to find High Scale Kirn in The Hole. May have to ask for some help with that bugger too.
Congratz.