Episode #2.3 - S2-E3
Other mistake: When the mother of a boy Arthur beats to death while boxing comes for revenge, she fires a single shot from a six-shot revolver at Arthur's head. Arthur then takes the revolver from her, ejecting 6 unspent bullets instead of 5. (00:28:24)
Other mistake: The Birmingham police officer, Moss, is still listed in the credits as Sergeant Moss. He held that rank in Season 1, but in Season 2 he wears inspector's rank insignia. Campbell does address him as Mr Moss, the correct title for an inspector.
Other mistake: When Polly tells Ada about her two children being taken from her, she says Michael was 5 and "Sally" was 3. When she goes to the seance she says her daughter would be 18, but shortly after that Tommy finds Michael and he is 17. Also, when Tommy tells Polly that he found the records on her children, the daughter's name changes to "Anna."
Suggested correction: The age difference could definitely be the case. Depending on the timing, she might be 18 years 9 months and he 17 years 1 month; in a month, Sally would turn 19 while Michael would still be 17. About the names: Since the children were taken from her, it would make sense that they changed the girl's name from Sally to Anna (I'm not sure how Polly reacted). Because Michael was already five, a name change wouldn't have been necessary - he was old enough to remember his original name.
