If "Whatever happened, always happened", then it might explain why we see Daniel crying in front of the tv in S04E02.
We know that Daniel later in his life will try to prevent the incident, the Swan being built, Desmond forgetting to push the button, 815 crashing, the Swan imploding, the bad Freighties (Keamy and co) coming to the island, causing Ben to move the island, causing it to skip in time, causing the Losties to end up in 1977.
What if, when Daniel sees the 815 wreckage on tv, he somehow feels that he, or actually his previous self, failed in his mission. Chronologically, the prevention already happened in 1977 and he finds out in 2004 that it didn't work.
Daniel possibly thinks that the Universe course-corrected 815 to crash anyway, but not on the island since there is no Swan to cause it. However, Daniel can't explain why he is crying since it is not a memory of himself, but of his previous self.
Allthough the wreckage is a fake, planted by daddy Widmore, it's still possible that Daniel THINKS it is real.
We know that Daniel later in his life will try to prevent the incident, the Swan being built, Desmond forgetting to push the button, 815 crashing, the Swan imploding, the bad Freighties (Keamy and co) coming to the island, causing Ben to move the island, causing it to skip in time, causing the Losties to end up in 1977.
What if, when Daniel sees the 815 wreckage on tv, he somehow feels that he, or actually his previous self, failed in his mission. Chronologically, the prevention already happened in 1977 and he finds out in 2004 that it didn't work.
Daniel possibly thinks that the Universe course-corrected 815 to crash anyway, but not on the island since there is no Swan to cause it. However, Daniel can't explain why he is crying since it is not a memory of himself, but of his previous self.
Allthough the wreckage is a fake, planted by daddy Widmore, it's still possible that Daniel THINKS it is real.
