Double continuity: In the beginning of the movie at 15 minutes in, Leigh receives an email from her boss, dated 14 july 2013. Later (68 mins), she gets another email dated eárlier, 13 july 2012 about an event happening 11 months later: the tiger article from the beginning of the movie...
Near the end of the movie, Leigh receives a postcard from Jason. Although there is a faint hint of a cancellation stamp, there is no POSTNET bar code at the bottom right of the card. Obviously, this postcard never actually went through the mail.
When Mel and Josh are reconciling about making a family together outside the school, the boom mic pole is visible on the car while they talk.