I love this movie but every time I watch it I come away with more things to question. For instance the very first time we see them watching Claire in her home I got the distinct impression she seems spooked by something, its almost as if she can sense someone watching her, which we know is Denzel's character and all the others watching the time window. He's a pretty smart guy because he seems to twig onto this as well with no one at all telling him that this is a time machine. Also the fridge has the message he made during this first observation so did another version of him already make the trip back? I got the impression that there are 3 versions of him. The one we see in the first half of the movie, the one that goes back, and the other version that walks up to Claire at the end, and there's a dead version in the water with the car that exploded.