Do You Take Dexter Morgan? - S3-E12
Other mistake: The marriage certificate for Rita's first marriage shows her date of birth as 04-19-1989 and Dexter states she married at 16. The marriage date is 08-16-1989, when she would have been 4 months old. She also would only be 17 at the start of the series (2006) if she was born in 1989. (00:13:45)
Our Father - S3-E1
Other mistake: When Debra is talking about her new haircut, she states that she has changed her hair "for the first time since she was 8." However in various flashbacks throughout the show she has drastically different hairstyles from her 'usual'.
Do You Take Dexter Morgan? - S3-E12
Other mistake: Debra is checking her email for the traffic cam photo of George King. The sender is labeled "Miami Metro Robbery Div." and the subject is "Photo of George King." However, after opening the email, the send is then a malformed email address of Det.Robertson.Robbery|MiamiMetroPolice.web with a recipient address of Debra.Morgan.Homicide|MiamiMetroPolice.wed (wed, not web), with a subject of "B. O. L. O. Match - George King." (00:26:38)
Answer: No, Harry is not the real father. While he did have an affair with Dexter's biological mother (Laura Moser), this was when she was his C.I. Dexter was already born at that point.