The phone number Julian wrote on the wall, supposedly Ambrose's number, is not the same as the phone number Ambrose wrote on his hand in a previous episode. It reversed the last two digits.
When Heather Novack phones in the amber alert for Julian she described Marin as a 30 year old female. However, Marin would have been 32. She was 18 when she joined Mosswood, probably 19 when Julian was born, and Julian is 13+ years old, making Marin 32.
During the search in the woods, Harry is reversed for a scene. His hair part is on the right side of his head.