When Dexter rolls the car near the end, after one complete roll, the car has clearly finished rolling, even bouncing slightly back the other way. Then from the next angle it continues rolling another half, onto the top.
Dexter was holding two plates and then turns and throws one. When Lumen stands up and goes to him, he still has two plates in his hands.
Dexter steals a car (Pontiac Grand Am) to take off to go rescue Lumen from an old camp ground. Dexter is speeding through the property, hits a piece of construction equipment, and rolls the car. A close up is shown of the car on its' roof, and the wheels on the car have Chevrolet's logo "bow tie" not the Pontiac "arrowhead"
While Dexter and Debra are in the briefing room talking, Deb says "I know what it's like to be taken" (referring to Dexter's brother who took her, The Ice Truck Killer) and immediately after Dexter has one his asides and says "she can't even say his name, Rudy, my brother" when in fact it was revealed that his name was Brian Moser, not Rudy. - While Dexter's brother's name is in fact Brian (Moser), he and everybody else mostly knew him as Rudy Cooper. So that name would be first on their minds.
Harrison's cake is an obvious fake, most likely decorated styrofoam. As the nanny carries it and places it on the table, with the position of her hands, a real cake would have fallen due to its heavy weight. She also carries it way too carelessly had the cake even been half the size.
The final scene when Sonya lights the candle, the ketchup bottle is perfectly blocking the candle. But when she sets the lighter down the ketchup and mustard bottles are both gone.