Interesting movie, bad happy ending

Rating: Null/10 (23 July 2011)

I love SF movies. In this one, the premise of projecting someone's consciousness into a past event is interesting. They made clear in the beginning that the movie was not about time travel nor alternative reality, and all those people are really dead and nothing he does would change that. As an example, in one iteration, he took "his" girlfriend out of the train and even so she was dead at the end of the 8 minute period. So, what happened happened and there's no way to change it. OK, that's clear to me and then they've changed that.
The movie should have ended when the life support was turned off (well, but wasn't he dead already?) and everybody on the train has frozen in the last iteration. But no, they have to put a happy ending even if it doesn't make any sense at all. So, they come up with a alternative reality or something like that. I just can't buy it.
It's not about two realities but there is only one in which everybody in that train was dead. Jake's "reality" was just a projection, a simulation made by a software (hence the name source code, I guess) that is driving his mind (his brain waves) to that train. Everything happened inside Jake's mind. So, I don't see how he could've survived after the plug has been pulled. The only explanation is that they needed a happy ending badly and didn't care if it would make sense or not.
Too bad, because without this nonsense ending the movie would be so much better.