Factual error: If you look at the band playing in the Regal Club the night the boy's mother first visits, the night where they first bring on the donkey, you'll notice that the drum kit used by the drummer in the band is, from what we can see, a 1980's Pearl kit, far too modern. (00:39:00)
Factual error: The recruits' hair is far too long when they parade after being conscripted. In those days Army recruits practically had their heads shaved - sideburns were shaved off to one inch above the ear (Army regulations). Curiously, this applies to the Staff Sergeant too - his hair would barely be visible under his hat.
Visible crew/equipment: Before Ronnie goes into kill George Cornell as hes getting out of the car look at the side window and you can see a boom mic reflected.
Factual error: When Reggie Kray goes to visit Frances' parents for the first time he is driving a 'D' registered car, this would mean that the car was from 1966. This event happened before 1966 as they were married in April 1965.
Visible crew/equipment: After the graveyard scene between violet and Ronnie, Ronnie is in a bathroom looking in the mirror. At the bottom right of the screen you can see a crew light.
Visible crew/equipment: After Ronnie gets out of bed naked, he looks in the mirror and talks to himself. A microphone can be seen at the bottom of the mirror.
Deliberate mistake: When the people come into the club looking for money off the owner a fight breaks out between the Krays and the people the Krays stick a sword through the gang leaders hand. But it quite obviously goes through the gap in his fingers. (00:35:10)
Factual error: Aunt Rose died in 1955 and not when Reggie and Frances were on their honeymoon. (02:44:35)
Continuity mistake: Ronnie chucks a man out in to the alleyway on the opening night of the club. The man holds a knife out at Ronnie - the height of it changes between shots. (00:43:50)
Continuity mistake: The amount of blood on the sword changes when it's taken out of the thug's hand. (00:35:10)
Revealing mistake: When the Krays are boxing for the first time, their mum comes in to break them up. She runs up to the ring where a member of the crowd holds the middle rope lower to help her get in the ring. The problem is, he pulls the rope before he sees her making her way to the ring. It can't be a coincidence as he lets go as soon as she's in the ring. (00:26:30)
Continuity mistake: When Reggies knocks the boxer out he falls by the ropes. Camera changes and he's moved away from the ropes.
Audio problem: When Reggie threatens the man outside his club, Reggie's boyfriend runs at him shouting "You stupid bastard..." and he is restrained by the gang. His lips never actually say these words.
