Character mistake: When Mike and the SAS team leader first meet, the team leader introduces himself as Will Davis, Captain. However at the near end when they say goodbye to each other, Mike addresses him as Lieutenant. (01:07:35 - 01:25:35)
Character mistake: Reacher asks the MP Sgt who her "DI" was in "boot camp." The Army doesn't have Drill Instructors or boot camp but rather "Drill Sergeants and Basic Training." Call a drill sergeant a DI and you'll be doing push-ups, seen it happen.
Character mistake: Twice over in the movie (when Healy wakes up and when March at the end of the movie drives to his place) billboards for The Comedy Store appear. The program of the evening features comedians such as Tim Allen, Richard Lewis, Robert Klein and "Elaine Boosler." So they misspelled Elayne Boosler's name. (00:10:50 - 01:48:35)
Character mistake: On the boat when Bishop went to rescue her, Jessica Alba says to the guy beating her up "get the fuck off me Ray." Then a few minutes later she says to the same guy "let me go Frank."
Character mistake: Being a doctor she leaves Frank the meds he needs to retain his feminity yet she doesn't leave what he needs to stop facial hair. Such things exist.