When Jessica was talking to Denver Martin in front of the boat repair shop, the one boat being worked on had a "CF" number on it which is a California registration. For Maine it should have been an "ME" registration number.
When the killer reveals how they did it, the flashback shows a supposedly unconscious victim in a vehicle being pushed into the water, however as the car hits the water, the brake lights illuminate.
Mort tells Jessica and Seth in front of Denver that Denver has no proof that the young swindler ever met his mother. The young swindler told Denver that he remembered meeting Denver's mother.