Character mistake: After accurately depth charging U-571, the German destroyer crew suddenly turns out to be almost comically and unrealistically incompetent at the end of the movie. Not only do they barely hit U-571 with their guns, but they also can't keep up with the sub. But even with both submarine diesel engines running flank speed (of which U-571 only has one badly damaged engine operational), a common WWII destroyer would easily be twice as fast as a Type VII U-boat. The destroyer could swiftly close the distance and could either ram U-571 or cross the sub's wake to bring all its weapons to bear and make it more difficult to get hit by the sub. Of course the destroyer doesn't do that but stays perfectly in U-571's wake for an easy kill shot from its stern tube. In reality, it was considered an incredible feat to sink a destroyer with a torpedo, since they were agile at full speed, could easily dodge torpedoes and had shallow draft. This destroyer crew however, seems actively trying to get killed.
Character mistake: When Maximus is talking to Marcus Aerelius, he mentions that his wife has black hair. But in the scenes where we see her, she actually has brown hair. (00:24:40)
Character mistake: Wilhelm Keitel was a field marshal, not an admiral as stated during the sentencing.
Character mistake: Patrick, being the music buff that he is, mistakenly claims that Huey Lewis' Fore! came out in 1987, when it was actually released in 1986.
Character mistake: When Barry and Rob are in the record store discussing Evil Dead 2, Barry makes a comment about someone offscreen making shotgun ammo in the 14th century. That plot point refers to "Army of Darkness" (the third installment the Evil Dead series), rather than Evil Dead 2.
Character mistake: Juliette Simone praises Eva in an across-the-room exercise but calls her "Aiesha." That is the name of Zoe Saldana's dance double.
Character mistake: James Lear is described as a Sophomore Lit major in the first scene, and at the end of the movie at Word Fest as a Junior.
Character mistake: After learning by telephone that he would be part of the Monkees and making records and a TV series, Mike says, "Man, it's a win-win situation." That expression was not in use in 1965; it didn't become widely used until the early 1980s.
Character mistake: Sam and Maurey were watching TV news coverage of Kennedy's assassination (11/22/63). When Petey got home (around 12:05 PM MST), he tried to change the channel, then said, "Mom, Maurey won't let me watch 'Rocky'." Laurabel/Mom said, "You know he watches 'Rocky' every afternoon." But school was let out early due to the assassination, so Petey would normally be in school at noon and therefore not be able to watch "Rocky" at that time in the afternoon. (00:21:30 - 00:23:17)