So Jack saw his father in the lobby of the hospital. And apparently that was MIB, yes? In fact, didn't the smoke alarm go off? That's pretty cool.
But HOW did MIB get off the island??? Here's a thought... wasn't he in the Donkey Wheel chamber when Locke turned the wheel? Soooo... couldn't he have been beamed away too?
What's that you say? That doesn't make any sense? How could Smokey be off the island and on the island at the same time? Beats me. What do I look like, a nerd?