Plot hole: When John retrieves the mail from the postman, Iris dashes outside. Less than 10 seconds after she closes the door, a car is heard, off-camera, honking a horn. Wouldn't John have found Iris so soon after that noise is heard? She doesn't seem to have enough time to allow for a search for her.
Plot hole: In the scene where Jason has his 5th birthday party, after the party it's night time and Bev is sitting on her front step alone when she is startled by her old friend from high school. They begin to walk and talk. She says to him at one point that she is 22. Now when Jason is born, it is stated by her dad that she is 15, so if it is Jason's 5th birthday that would make Bev 20 years old, not 22.