I loved the movie plot, but I got sad on how it ended. For a movie that deals with time traveling, they should pay special attention to such things!

First, the mexican guy. They make it very clear over the movie that his truck's tire breaks, but on the ending it doesn't happen and he just arrives nicely to the station.

Then we have the police officer arriving very late on the station. He's always able to reach Frank. As Karen knows Frank will know about Rayanne and freak out and take her out, she'd not ask the police to go slower, she'd ask him to reach them before they get to the station and be ready for Frank. If he'd do and know about the gun, they both together could arrest Frank. Even better, she could do as she did before and take the gun, then make him stop the car and leave unarmed to be arrested.

Then the family. They don't get to Karen before Brian does, at least they aren't shown, still they arrive on the station first.

It feels like the story writer/director got lazy to write a proper ending and just rushed it to a perfect happy end where all the bad guys die.