Revealing mistake: When they are watching football, the mom walks in and says something to the family while she is holding 4 Pepsi cups in a cardboard cup holder with only one hand. If the cups were actually full, the way she was holding it it would have tipped over.
Revealing mistake: In the scene where Brian Clough is at home you can see double glazed upvc windows, even though they were not around until the 1990s.