Actually I talked to that one. In my long post, above I stated that I fought the one in the wine cellar.
Yes, I saw that. You also said you thought the one in the cave was George's murderer. So I'm not sure what to think. It's possible to ask the one in the cave about George mistaking him for the other vampire, but he won't know what you're talking about. You mention talking to the one in the cave and killing the one in the cellar. But did you also kill the one in the cave and talk to the one in the seller?