If anyone is still unconvinced that the detonation of Jughead actually causes the Incident, then consider the facts that we know:
- On day 3 after Jack, Hurley, Kate and Sayid come to 1977, Daniel Faraday returns to the Island.
- On day 4 (the next day), he convinces Jack and Kate that they aren't meant to be in the past, but that they have a chance to set everything straight--by "preventing" the Incident with the use of the hydrogen bomb. As we saw, this idea greatly appealed to Jack. To note is that this is the first time Faraday has ever contradicted his own, previously concrete, "Whatever happened, happened" theory.
- On this same day, minutes after explaining his full plan to Jack and Kate, Daniel is shot and killed by his own mother, Eloise Haw…