When Lila first walks up to Dexter after the Narcotics Anonymous meeting she's shown with her right hand holding the strap of her purse and her left hand in her pocket. When the camera changes mid sentence both hands are holding each half of an already split Oreo cookie.
When Debra is speaking to Special Agent Lundy after interviewing a woman and telling her that her daughter won't be found, part of her hair is in front of her right eye. In the next clip of her, her hair is up behind her right ear.
Rita asks to see Dexter's "newcomer chip" when he gets home from his first meeting.
Alcoholics Anonymous uses aluminum medallions that say 24 Hours. Narcotics Anonymous uses white keytags that say Welcome on one side and Just For Today on the other. Dexter would've gotten a keytag, because it was an NA meeting.