Factual error: Early in the movie when the interior of the downed aircraft is shown (underwater in Chesapeake Bay), with the eerie picture of Dutch's wife and the congresswoman's husband sitting underwater in first class with their hair waving slowly in the current, they are shown on the right side of the aircraft (the left side as we are looking at them, but the right side of the plane proper). Yet, when the airline representative is discussing this "problem" (non-married-to-each-other people apparently flying as a couple), they are announced as sitting in row X (don't remember), seats A and B. Aircraft seating is always done from left to right - i.e., the A and B seats would be on the other, or left, side of the aircraft.
Factual error: Just as Ralph Fiennes is getting out of a car to run across the road you can see, just as he steps out, road markings that were not around in the mid forties and that weren't on the road in a shot just previous when you could see the road behind Fiennes in the car window. (01:09:05)omegaman3000
Factual error: Set in the summer of 1977, serial killer David Berkowitz is seen throughout the film wearing a US Army woodland camouflage pattern field jacket. The Army did not start using these jackets nor were any ever made until the early 1980's. They were all solid green until then.
Factual error: Kevin Coster's arrival at spring training is set up by a shot of a beach scene with the caption "Spring Training Lakeland Florida". The shot was not filmed in Lakeland and is not at all representative of this town. Lakeland, Florida is located near the middle of the state, and while it does have many lakes, it is not on the ocean. (I suspect this shot was actually filmed in Ft. Lauderdale or Miami, which is at least 200 miles away.) (00:05:56)
Factual error: When Homer and Candy go to the movies, the theater has stadium seating. This seating style in theaters wasn't used until much later, not in the early 1940's, and certainly not in Maine.
Factual error: In the scene where Arthur tries to convince Gertrude to not force her husband to "retire from public life" you can see (in the close up shots) that his right ear has been pierced twice which is inconsistent with the time period.
Factual error: All of the computers show a Mac OS when they're booted up. However, when Peter is shutting his computer down to try to escape his boss, the computer shuts down to a C: prompt. For those not technically minded, a C: prompt is only seen on IBM-compatible PCs, never on Macs. (00:19:20)
Factual error: When Heather pulls up in her car and confronts Oz after seeing Stifler making fun of her on the Lacrosse field her car has an actual Michigan license plate on it. One of the producers even pointed it out on the DVD thinking that it was a great attention to detail. The only problem with that is the plate is on the front bumper. Michigan does not have licence plates on the front, only in the back. (00:41:10)
Factual error: Trying to cozy up to Ike, who she knows to be a Miles Davis fan, Maggie gives him a battered-up LP of Davis's "Kind of Blue" album, which he tells here is very rare. Truth is, "Kind of Blue" is one of the best-selling jazz albums of all time, and is not rare at all. Furthermore, the album and initial CD pressings had been (inadvertently) mastered at the wrong speed; the mistake wasn't corrected until relatively recent CD issues. The long-player is, in other words, virtually worthless on any count, especially in a jacket as beat-up as the one Maggie gives to Ike.