The rabbi tells David that he and Buddy will have their bar mitzvah together, but David is nowhere to be seen at the service.
During Buddy's Bar Mitzvah ceremony, he mentions his mother, wife, and friends, but as the camera pans the congregation, Pickles (his wife) is not present. Neither is she present in the group shot at the end.
Rob mentions that the Torah was written 5000 years ago. Even by the most liberal estimate, no part of the Torah could have been written more than 3500 years ago.