Let's Give the Boy a Hand - S1-E4
Factual error: When Dexter and Doakes are looking at the severed foot wearing a soccer cleat, Dexter states, "The foot was severed between the tarsus and the metatarsus." However, the foot was severed proximal to the tarsus, through the tibia and fibula. The cut was easily too high to be between the tarsus and metatarsus. (00:16:45)
Factual error: When the American team almost assassinates the vice-chancellor in the beginning, the German team comes in guns blazing. No special forces unit in the world would do that. They would have suppressed weapons, and use their ammunition diligently.