Factual error: Pretty much every medal ribbon shown appears to be completely made-up.
Factual error: At the beginning of the movie, Jason Sudeikis pops out of a door wearing a Jurassic 5 T-shirt. Problem is, the artwork on it is from the cover of Feedback, their 2006 album. The scene, as the introductory caption says, is supposed to happen in 2002. (00:00:55)
Factual error: The delivery van bringing gear for the walk has a 718 area code on it. That area code did not exist until 1984.
Factual error: In the fighting scene in U-Bahnhof Alexanderplatz the underground trains move much faster than in real world. Alexanderplatz is a railhead station. The trains would either crash into a wall or would not have enough room to accelerate that fast.
Factual error: The good guys manage to take over key parts of the prison by homebrewing some chloroform mixing alcohol and bleach in a cute little spray bottle, crawl through the ventilation system and slip in the room a couple dainty squirts. Which instantly knock the guards (one of them with a full face helmet) out. All of this is of course bahooey; chloroform is really volatile and would never make it across the room, and the dosage is absolutely negligible. If the gas were this powerful (which is not) would have KO'd the two agents anyway while they were doing this chemist stunt preparing the gas itself in the tiny broom closet.
Factual error: When Tony first goes to Johnnie's house a satellite dish can be seen mounted on the house in the background. Not in 1973. (00:57:00)
Factual error: Dev Patel is standing in front of Trinity College's statue of Issac Newton. Directly behind the statue is a marble wall with names carved into it. This wall is a list of the members of the college who died in World War II. It would not have existed in 1914.
Factual error: During the drone strike, they show MQ-9 Reaper, which is prop-driven, but play a jet engine sound effect.
Factual error: The producers took a lot of pride in using period-accurate furniture and clothing. But the family's house and furniture aren't remotely accurate for their actual situation. The table, the chairs, the house with a sleeping loft - all those took technology and manpower that they didn't have, and we've already seen that they had nothing to trade either. And they have more furniture than could have fit in that wagon.