When Nida goes to vomit in the bathroom, you can see the toilet lid is up. In the next scene, she's lifting the lid just in time for her to vomit.
When Officer Suzie is about to leave the bar she puts on her hat, then in the next shot she is shown putting her hat on again.
The penultimate day of the murders, April 29th 1979, was a Sunday, but in the UK at the time Sunday trading laws would have meant that the store would have been closed.
Detective Inspector Fisher is seen reading "Smiley's People" by John le Carré. The author's last name is misspelled on the book's front cover.
The nuclear detonations taking place at the end are depicted incorrectly. The depicted detonations produced instant fireballs and mushroom clouds, but before that, nuclear detonations should have produced a brilliant flash of light many times brighter than the midday sun.
The slang verb "blanked," meaning "to ignore" someone, did not exist in the 1970s or even in the 1980s.
Despite being set in May 1979, there are pop culture elements featured in this episode that didn't take place until later that year - the release of "I Don't Like Mondays" by the Boomtown Rats and the broadcast of Assignment One: Part 1 (1979) didn't occur until July, while "One Step Beyond" by Madness was released in October.
However, there is a deliberate artistic licence used during the episode, such as with Boney M being at No.4 in the UK Charts with Ra Ra Rasputin - while the group were at No.4 at that time, it was with "Hooray! Hooray! It's a Holi-Holiday", not the Rasputin single which had charted the previous year.
However, there is a deliberate artistic licence used during the episode, such as with Boney M being at No.4 in the UK Charts with Ra Ra Rasputin - while the group were at No.4 at that time, it was with "Hooray! Hooray! It's a Holi-Holiday", not the Rasputin single which had charted the previous year.
When Gaap uses the phone to call for advice, on the face of the phone it says the area code for Tipley is 01632. In the UK, 1's weren't added to area codes to make them become 5 digits until 1995.
The book that detective inspector Fisher is seen reading - "Smiley's People" by John le Carré - was published in November 1979, several months after the penultimate day of the murders, April 29th 1979.
In the car chase scene, just before Nida starts ramming Michael's car, they both appear to be driving on the right hand side of the road. The UK drives on the left.