When Alice tells Luther that anything bad that happened between them is in the past, Luther responds, "the past isn't dead. It's not even past." This is a close paraphrase of one of William Faulkner's best-known quotations ("The past is never dead. It's not even past"), originally from his 1951 book Requiem for a Nun. Two years after this episode aired, the Faulkner Estate sued Sony Pictures Entertainment for copyright infringement over another paraphrase of the line used in Woody Allen's 2011 movie Midnight in Paris; the estate lost that case on the grounds that the line constituted a small enough portion of the whole work to be considered fair use.
This episode stars both Sean Pertwee, son of Jon Pertwee who was the third actor to portray The Doctor in Doctor Who (1963), and Paul McGann, the 8th actor to portray The Doctor in Doctor Who.
An excerpt of this episode, when Lynch finishes shooting several officers from the rooftop, is shown in a side-by-side webcam RPG used as part of evidence in a murder trial on episode 6, set 1 of SILK.
During this episode, the character Owen Lynch (Sam Spruell) uses the phrase, 'Ever get the feeling you've been cheated?' This is exactly what Johnny Rotten says at the end of the Sex Pistols last gig in USA before they split.
The unit that both Lynch's were assigned to (46th Commando, Royal Marines) was an active unit from August 1943 till January 1945.