Continuity mistake: Early in the film, Michael talks to Harry Boland on a boat. During this scene, a cigarette appears in Boland's mouth that was not in the previous shot. (00:40:40)
Continuity mistake: When Michael Collins searches through the files in the castle he takes the only photograph from his file and shows it later to Harry Boland. But when the file is given to Soames, the photograph is back in. (00:30:30 - 00:52:15)
Suggested correction: The British authorities in Dublin Castle were capable of making copies of photographs and reproducing them. They would not have had only one copy.
Continuity mistake: When Michael Collins joins the first cabinet meeting after DeValera's return he puts a briefcase on the table in front of him and takes out some papers. When the camera angle changes the briefcase is gone. (01:09:45)
Continuity mistake: There's one scene where Michael Collins talks to Ned Broy standing on a small pedestrian bridge while a train passes overhead. From the railing construction you can tell that the close-up was taken at a different place than the wide shot. (00:51:05)
Continuity mistake: When DeValera returns from America Joe O'Reilly hands him a paper with the news. It is folded in a way that shows cover outside, but when DeValera opens it the crease is the other way. (01:08:45)
Continuity mistake: When Michael Collins announces to his men that all collaborators will be shot his hair changes from messy to perfectly combed between shots. (00:30:50)
Continuity mistake: There is a scene in which two Dublin United Tramways Corporation trams pass in opposite directions. Neither has its trolley pole in contact with the overhead electrical wiring, so the electricity must be jumping the gap to the motor in some way unknown to physics! The trams were, of course, fakes with a petrol engine.
Continuity mistake: When Ned Broy comes to Vaughan's the night he gets killed the receptionist is sleeping on the counter. He wakes up a few minutes later when the hotel gets raided, and next to him there is a bell that hasn't been there before. (00:58:50)
Continuity mistake: After Kitty wakes up Michael and Harry, the way she holds the water can changes between shots. (00:14:05)
Continuity mistake: When the armoured car interrupts the ball game a player scores a goal to mock the attackers. The player who receives the ovations and gets shot in return is not the one who scored the goal, and there are bullet holes in his tricot even before he gets hit. (01:06:05)
Continuity mistake: When Michael Collins and his men raid the police station they throw torches on the roof. A second later the whole building is on fire, and the policemen run out coughing and gasping for air. However, when the IRA people go in to get the police guns the air is quite breathable. (00:15:25)
Suggested correction: When the policemen exited the building, they opened the doors, which let much of the smoke out, allowing the IRA men to enter without succumbing to smoke inhalation.
