When Adam and Kyle destroy Rachael's painting it goes from being clearly torn apart by both an ax and knives in one shot to being whole again when they try to set it on fire.
In the doctor's office, Adam's mother gets up to look at a picture on the wall and her hair is tucked in her jacket. In the next shot, her hair is back out.
Adam stops jogging in one shot at the streetlight, but in between shots he's still running in place.
During Adam's surgery they show the surgeon using laparoscopic surgical tools and the surgeon is watching images of the surgery being performed magnified on a screen, also used during a laparoscopic surgery, yet Adam's long scar down his back clearly shows his surgery was an open procedure.
When Adam is in Dr. Ross' office with his mother and father, his mother inspects a diploma from "Washington State University Medical School". Washington State University does not have a medical school.
When Adam tells Kyle he has a tumor, Kyle says, "Well are you going to be okay?" and his mouth doesn't move, then after that he says, "What are your chances?" and it almost overlaps.
When Kyle honks his car horn for Adam, the camera's reflection can be seen advancing toward the vehicle's side.
When Adam is running in Seattle at the beginning of the film, the Lion's Gate Bridge in Vancouver, BC is seen in the background.
Road signs, including One Way and Do Not Enter, have no text as they are Canadian road signs. The film is set in Seattle, Washington, USA.
While set in Seattle the movie was filmed in Vancouver. In one of the opening scenes when Adam and Kyle are walking down the street there is a sign in the background for Lotto 6/49 which is a Canadian lottery.
We learn at the begging of the film that Rachel(Bryce Dallas Howard)
does not live in Adam's (Joseph Gordon-Levitt) house, from the fact that she asks about her stuff and he responds that he put them in a closet, but Rachel has all kind of shampoos in his house like she lives there permanently. It really does not make sense.
Kyle mispronounces "whilst."