We know Smokey (or we pretty much know) that he can take the form of dead people if he has access to either their bodies (Christian/Yemi) or if the person he's appearing to/as is special (Walt,Ben). And so we see both Charlie and Christian in the real world. Crazy as Hurley would believe? No, Smokey (or Jacob, if you're like me and still believe Jacob and Smokey are one in the same) can go off-island.
I think this is substantially proved by the
smoke alarm going off
