Other mistake: At New York ATC, the radar shows American Airlines Flight 11 disappearing over Manhattan, indicating that it has just crashed into the North Tower. This occurred at 8:46 a.m. Around a minute and a half later, Sgt. Jeremy Powell at NEADS directs the scrambling of fighter jets in search of American 11. He states that the time is "0846" (meaning 8:46) - should be 0847. (00:34:55 - 00:36:17)
Other mistake: On-board Flight 93, Mark Bingham's conversation with Tom Burnett about sports is repeated twice in two separate scenes. You can tell if you listen out for Bingham's line, "You take out all your aggression and all your, you know, all your shit for the day." The dialogue is heard in the background the first time around and then given more focus the second time. (00:46:49 - 00:55:35)
Answer: Muslims are supposed to remove their pubic and armpit hair at least every 40 days. It is part of being clean and they would want to be as clean as possible while committing an act on behalf of their religion.
Myridon