Character mistake: Louis Greene, Masuka's new intern, is asked to find the person who purchased Rudy's prosthetic hand. He is unable to do so; however, as a consolation, he says "I installed a modded-up Intel chip to overclock your CPU." You can overclock your CPU, but you don't need another chip to do so.
Other mistake: While Dexter's searching for info on Travis Marshall on his laptop, he opens the DMV Records window with an image of Marshall's driver license, and in the closeup at the bottom of the license it reads "Operation of a motor vehicle constitutes consent to any sobiety test required by law," with the word "sobriety" missing the letter "r." Additionally, under the image of the license it reads "Issued: 10-12-2006", but on the actual license image it reads, "DOB: 11-24-1977, Issued: 09-23-1990, Expires: 09-23-2012." So that means Marshall was not even 13 yrs old when he got his license, and the license won't expire for 22 years. Also, when Brother Sam knocks on the door Dexter clicks back onto the MOA website, and if you care to pause the screen note the word "Exibit" is missing the letter "h."
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.