Continuity mistake: Dexter's hybrid SUV changes often. Sometimes it has satnav, sometimes it doesn't.
Continuity mistake: Dexter browses the book shelf at Travis' house. The camera pans across, revealing a book titled "Apocalypse Bound" situated at the right on the shelf. When Dexter takes the book off the shelf, it is then shown as the fourth book from the left. When he puts it back, the empty gap where it used to be now appears to the far right on the shelf. (00:25:50)
Just Let Go - S6-E6
Continuity mistake: When Travis meets his sister at the school she works at, a chalk board with nothing on it can be seen behind Travis. A couple of shots later and there is a piece of paper attached to the chalk board. (00:30:35)
Continuity mistake: In Season 6, Episode 10, Dexter and Harry are in the motel room where Travis was staying (timestamp 1). Dexter decides to post on Gellar's blog (impersonating Gellar), and the screen on the computer shows the post date as Sunday, November 24, preceded by a Sunday, November 20 post. Aren't Sundays supposed to be a week apart? Then in episode 12 (timestamp 2), Travis is in Dexter's apartment and sees the poster for the Noah's Ark school play. The date posted for the play is Saturday, October 8, ie. in the past compared to the earlier episode. Plus If November 24 were on a Sunday, then October 8 should have been on a Tuesday. (00:09:20 - 00:30:20)
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.