Before pouring it on the cornflakes of the lad he is interviewing, Masterson sniffs the milk to check it's fresh. The bottle is a "Dumpy", introduced in 1980, a taller bottle with shallower shoulders would have been in use.
The character of Halliwell, who is black, is supposed to have been in Northern Ireland with the Coldstream Guards just after Bloody Sunday, which was in 1972. There were no non-white guardsmen until 1988.
The Miskin character claims to come from Dorset, then goes on to specify Southampton. Southampton in in Hampshire.
At 19:24 when Dalgleish and Miskin are walking out of Campden House, Bertie Carvel's fly is undone.