The last 5 or so minutes of "Source Code" seemed to be tacked-on so the "real ending" wasn't so grim and depressing. I've heard some fan theories that explain why the official ending is grim, but it takes some mental gymnastics to accept it. I feel like Duncan Jones was forced to add a sappy ending

How did Monica not know Ehrlich was the bidder? Anyone?

I was thinking about this….what if it was the gun dealer. He'd know Mike was there.

The Y-shaped lights outside the Waffle Hut that frame Peggy match the Y-shape in Hank's drawing, both symbolize death. Though it is obvious, considering how Fargo is, I think this foreshadows Peggy's demise. Since Hank created the pictures though, I think it might indicate he's the one who gets her.