At the end when Janet is in the kitchen and thinks she hears her mother-in-law calling her name, she goes to the doorway and her sweater is not tucked in. When she turns around for the next full body shot her sweater is tucked in.
When the family is having breakfast, we hear daughter Shawn complain that the milk is nonfat. But the milk has a red cap. Skim milk never has a red cap, it is always yellow or blue.
The shadow of the team filming can be seen reflected in a car at the beginning of the movie.
When the Smurls are driving home from camping, John calls his wife Mary "Kate", which is their granddaughter's name.