So wait......do the Dharma people know about time travel or not? In the season premiere, Chang tells that guy in the Orchid that they're drilling because into the rock because there's energy there that will allow them to manipulate time. So, doesn't that mean that the higher ups at Dharma know that something about their mission there has to do with time travel? So when Sayid tells them that he's from the future, do they just totally dismiss that out of hand, or might they think that he might actually be telling the truth?
The caveat is that we don't know when that scene takes place. It depends on what happened to Daniel. There's a good chance it happened before "LaFleur" chronologically but it could just as easily have happened after. We can assume (I think) that Dr. Chang at least suspects
time wackiness by the time he gives Jack his orientation in "Namaste".
Also the Dharma "higher ups" aren't on the island. The one guy who could credibly know about time travel during that period wasn't at Sayid's interrogation, so it's possible that Horace (who's running the show ON the island) has no idea.