When we see the truck through night-vision goggles in the episode's opening scene, the driver is on the right side of the truck. When the camera pans out to reveal the truck from a different angle, he's on the left side.
When the doctor positions the retractor and cranks Loeb's chest open, we can see that the top of it is parallel to Loeb's body, but then when he steps back to look down on it, the retractor has turned 45 degrees.
The uniforms worn by the German prison guards look nothing like real German police or prison guard uniforms. Uniforms of German prison guards don't have badges.
The uniforms worn by the prison guards are actually old style German Bundeswehr (German military) uniforms. The German military has no authority at all in all things internal. Mistake on top of the mistake: The guards wearing badges regarding the federal states of Germany. On the German military uniform is no such thing used or allowed.
The aerial shot of the Frankfurt airport shows the railway-station as it was prior to its reconstruction in 2007, the long glass-bubble north of the highway (shot was filmed facing south) has been replaced by a multi-story hotel. In addition, none of the interior shots were taken at Frankfurt airport, which has a glass-and-steel-girder look.
Agent Dunham says that she's from "Homeland Security" when in fact the FBI is under the Department of Justice, not the Department of Homeland Security. However, she is working as part of a special Homeland Security task force; so while she technically works for Justice, saying she is from Homeland Security is accurate.
The prison in Frankfurt is announced as "Wissenschaft Prison" in the titles. This is a literal translation of "Science Prison". The word "Wissenschaft", however, can't be used like that at all, not even in a German-English compound. The title should either read "Wissenschaftsgefaengnis" or "Science Prison".
All German-speaking characters speak with heavy American accents, except for the prison warden. Moreover, the announcements at Frankfurt airport are also spoken in American accent, and they don't follow the protocol for such PSAs at German airports.
During one of the final scenes, Dr. Walter Bishop says "of course, horizontal line." As shown, his son had obviously drawn the lines vertically.
The aerial shot of the Frankfurt airport shows the railway-station as it was prior to its reconstruction in 2007, the long glass-bubble north of the highway (shot was filmed facing south) has been replaced by a multi-story hotel. In addition, none of the interior shots were taken at Frankfurt airport, which has a glass-and-steel-girder look.
During the raid on Smith, Agent Dunham was in Frankfurt" and Bishop was in "Boston" but the position of the sun is the casting the same shadows, as the timezone is 6 hours different it should have been either early morning in Boston or late evening in Frankfurt not mid afternoon in both.