The house shown at about the six minute mark has also been shown in an episode of midsomer murders and Lewis in season 6 episode 4 'the indelible stain'.
Guest star Josie Lawrence made frequent appearances on 'Whose Line is it Anyway?' with Caroline Quentin, who played Maddie in the early years of this show.
Around 19 minutes, a character asks Jonathan "you know when you're really struggling to really see the relevance of Nylon hosiery?" Jonathan was indeed struggling to see the relevance of hosiery in the series 2 episodes The Problem at Gallows Gate 1 and 2.