Another big clue on time being a important part of this show. Only fools are enslaved by time and space. Time manipulation or time differences is huge.
My theory is that this is what they were studying about Walt. He had some sort of super-natural ability to not be enslaved by space, thus his appearances to Shannon & Klugh's questions to Michael re: if he had ever been somewhere he wasn't supposed to be.
This idea of "Only fools are enslaved by time and space" may contribute to the explanation of other occurrences, also...from Christian to the black horse, etc. Still working on this one...obviously. lol