Revealing mistake: After Duke hears noise coming from the stairwell he locks the doors at the end of the hallway. After Duke shoots Parelli it cuts to the police firing at those locked doors, and when the doorknob blows off we can see that it's only a glued on doorknob, with no hole in the wood door, so it's impossible to have actually locked it.
The Anderson Tapes (1971)
1 revealing mistake - chronological order
Directed by: Sidney Lumet
Starring: Sean Connery, Martin Balsam, Dyan Cannon, Ralph Meeker
Other mistake: During the heist the Mayflower truck is parked at the building's 91st Street entrance, and the police have blockaded 5th Ave at the corners of E. 90th and 92nd Streets. When the guys try to flee the truck is driven down 91st so as to turn onto 5th Ave, and after the driver's close-up there's an overhead wideshot of 5th Ave and the truck should be coming from 91st, but it's actually coming from further up - towards 92nd Street, with the corner of 91st in front of it, which is impossible since it should have made the turn at 91st.
The Kid: America, man! You know, it's so beautiful I wanta eat it.