The big mirror-surface sculpture the two walk up: we see Gyllenhaal but the reflective surface shows that his character is seeing the other man's body.  As to where HIS mind went, since the past was changed, is an unanswered question.  The rule that's established, "this isn't time travel," existed TO BE broken, it seems to me--that is, it wasn't a rule at all.  This seems to have been one of the first times this methodology was tried. 
SteveZodiak wrote:
The confusion is that he was actually traveling in time, but merely reliving a time sequence, the outcome of which could not be changed in the real world. My confusion is that it at first appears that he alters the outcome in what I figure became an alternate reality. A split time line, but then the story goes further and that proves not to be what happened at all. Now I am confused because if this is real time now, then who is occupying the body that didn't die? Wouldn't it be the original owner? I worked out my own possiblity, but it requires way too much speculation. The ending is just not clear to me. I must have missed something.  
I think you left "wasn't" out of your first clause there.  He's told he is not traveling in time; the train will "always" be destroyed in an explosion.  But it turns out that he IS traveling in time, because he does alter the future--and now he's in that alternate time line.  I don't remember what happens in the "original" time line--I think that since the train was saved, the people in the lab are doing something else.  Gyllenhaal's ruined body dies in the >original< time line--which is what sets his mind free to change reality.  Or at least that's how I read it.  The director, familiar with time travel conundrums and paradoxes, says he carefully worked everything out. I suspect he did, and that most of these questions can be answered on a second viewing.

Last Edited By: Bill Warren Apr 28 11 2:06 PM. Edited 1 times.