[IslandNiles]

KidMoe, I wasn't trying to imply that the ending didn't make sense. I just would have preferred for that element not to have been introduced at all. Spoilers follow!

Spoiler

I felt they cheated a bit at the end, that they broke the rules established throughout the film. Those people on the train were dead, they were beyond help. That was made abundantly clear, as was the nature of the source code. I know there was some doubt about what could be achieved, but that was only ever in Colter's mind. Everyone else was very clear about how it worked.

I thought it was a nice ending that he chose to live out his last eight minutes in the source code, and then Goodwin let him go. For me, the last few minutes just diluted it, and betrayed what had been established as the premise.

Actually, having re-read your post, there are elements I disagree with. Throughout the film, there was no evidence of:

Spoiler

A new reality being created each time. As far as I can remember, anyway. Nor did he ever live beyond Sean's death. He lived out the eight minutes and then his consciousness returned to reality, such as it was. Each time, Goodwin and co were getting more desperate, because time was passing and the dirty bomb was becoming more of a threat.

The last source code was the only time Sean was saved, as far as I remember. But you're right - in a previous loop he had lived slightly longer than the eight minutes, until he was hit by the express train. I did wonder what would happen if he hadn't been hit.