At the end when Dexter and Astor are in front of her grandparents' house, she gets out of the SUV and grabs her backpack and throws it over her shoulder, but between shots of her picking up Harrison's toy and heading into the house, the backpack appears and vanishes. She is not wearing it as she and Dexter walk up to the front door.
Suddenly the bathroom in Dexter's house has a door. It used to be an open bathroom with a wide archway as can be clearly seen just at the end of Everything Is Illumenated (2010).
When Dexter is giving a beating to Barry, he tells him that he just punched his liver (located on the right upper part of the abdomen) when he's actually hitting him on his left side (thus more likely to injure the spleen).
When Dexter is getting a specimen from the vial that Chase wears around his neck; he says he's using a 30 gauge needle to obtain his specimen. In fact he's using a 19 gauge needle; the needle he's using has a green hub. That is the color code for a 19 gauge needle.
Quinn's hypothesis about "Kyle Butler" being Dexter was never proven wrong. Not even an argument against it was made. There is no reason for him to let go of it.
He indeed hasn't let go of it but was told officially by both the FBI and Laguerta that he couldn't show the drawing to Jonah Mitchell so he is trying to prove that Dexter is nefarious in other ways.
At 45:49, Det. Quinn throws cash on the table offering a severance package to Liddy, but the money is clearly fake as it reads, "FOR MOTION PICTURE USE ONLY."
When Dexter is taking Astor home with his car, you can see the camera in the rear-view mirror.
Dexter drives along a street and passes by a Rock Bottom Brewery and Restaurant. The show is supposed to take place in Miami, however, there is no Rock Bottom to be found in Miami or anywhere in Florida for that matter. There is, however, a Rock Bottom in Long Beach, CA.
The girls are supposedly found at Bayside. However, the place shown does not even remotely resemble Bayside. Bayside is essentially a two-story open air mall with a large Hard Rock café next to it. There is no large marina across the bay as shown in this scene.
Angel tells Deb that his report backed her story 100 percent. "Not that it mattered. The brass backed my wife." Looking at the relationship LaGuerta has had with Deputy Chief Tom Matthews and how he likes Deb that is highly unlikely.
Whenever Dexter kills anybody, he starts by making sure the victims are actually guilty. It is an essential part of his "code". But when he beats up Olivia's stepfather Barry, there is none of that, only the claims of his unreliable and manipulative stepdaughter Astor with whom Dexter has famously failed to connect over the years and whom he knows to lie to him all the time.