Some may feel it was a bit underhanded, manipulating the audiences’ expectations and assumptions based on a previously well-established structure just to make a last minute reveal all the more shocking. I wouldn’t even say those people are all that wrong. They’ve done it before, most noticeably when introducing the flash forward concept at the end of last season. Just as that episode introduced a new narrative structure we’ve since learned to look for, after this episode we’ll now have to be on the lookout for multiple structures occurring simultaneously in one episode. The difference, of course, as Dr. Bitz pointed out, is that this time the nature of the flashback was concealed solely to make the ending surprising, and served no other narrative purpose.
This episode, obviously, was about the death of Jin, in more than one way. After Jin emphasizes to Sun that the controlling, angry Jin of the past is dead, we learn that the new Jin, the one we’ve come to know and love, is also apparently destined to die. The Jin that was born on the island is destined to die there. Obviously, the notion that island-Jin is a much better person than flashback-Jin is nothing new to the audience; however, his proclamation to Sun is significant because it comes after he discovers Sun’s affair. It seemed clear that Sun feared above all that the revelation would bring flashback-Jin roaring back. That it didn’t, that island-Jin prevailed when faced with his biggest challenge, confirmed not only how much he’s changed, but that he will stay that way, all the way to his now-fated demise.
The two married men bonding on the boat; one of the few scenes we've ever had between two people just sharing information, not plot exposition.
Jin’s tombstone listed his date of death as 9-22-2004, the day of the crash.
I didn’t notice it the first time through, but in hindsight, Jin’s cell phone in the flashback was just slightly out-of-date in the same way Jack’s cell phone in the “Through the Looking Glass” flash forward was slightly too modern.
Is Jin really dead? I don’t believe Sun said anything at his grave that specifically referenced his death; perhaps the “funeral” was simply Sun mourning Jin’s absence (because he couldn’t leave the island for some reason). Or perhaps, as Dr. Bitz suggested, I’m overthinking things, and Jin is dead. He did get a DUI, after all.