Continuity mistake: When Dexter and Rita are having dinner at Miguel's house, his wife drops a glass. She sets 2 other glasses on the island in the kitchen. After a cut to another shot the 2 glasses are now on the counter by the sink, before she bends down and picks up the glass she dropped.
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.
Continuity mistake: In the scene where Dexter is playing a video game on Miguel's office computer, Miguel is shown to close the game down. But in the next shot the game is visible on the screen before disappearing again in the shot afterwards. Additionally, the video game shown is Halo 3, which is only available on Xbox 360. When Miguel 'closes' the game, he is actually alt-tabbing from a "TWVidpla" window to "Plaindesktop.bmp," and a laptop battery indicator is visible.