Revealing mistake: About 3/4 through the movie, Bradley Cooper and his wife are talking in a bedroom or nursery. He takes his daughter and holds her - the baby is clearly fake.
Continuity mistake: About where she's heading 5 miles, in one shot Cheryl's (Reese Witherspoon) watch and bracelet are on her left wrist and in one shot they are both on her right wrist. Then throughout the rest of the film, Cheryl's watch and bracelet are on her left.