My issues don't lie with the movie science here, but with the script because Source Code is such a fun concept that, unfortunately, plays out like a first draft. There is so so so much time wasted on Jake Gyllenhaal arguing with the science people that the movie spends time actively fighting against showing what I want to see in a time-loop film—the actual mystery-solving by trying new things out. When he finally understands that he's been placed in someone else's body to stop a bomb on a train (something that should have been laid out at the very start of the movie), instead of an obligatory live-die-repeat montage, all we get is a quick flash of him blowing up a bunch of times, solving most of the mystery off-screen. There are definitely moments I love in this movie, and when it leans into the time-loop scenes, it's exciting, but for a film entirely predicated on that concept, those scenes are just too far and few between for me.

Another thing that bugged me was the whole mirror gag where he looks like Jake Gyllenhaal to us and him but a random dude to the people in the source code. We've never met any of these characters, so why not just have Sean Fentress look like Jake Gyllenhaal??