The part of Alfie Wilkinson, one half of the student trivia team, was played by Lawrence Fox's younger brother, Jack Fox.
When Hathaway says of his missing guitar "her price is beyond rubies" he is quoting the Bible (Proverbs 31:10): "Who can find a virtuous woman? For her price is far above rubies."
The quiz moderator says one section is "only connect". This refers to the UK panel quiz show, Only Connect (2008).
Alan Davies, who plays quiz master Marcus Richards (allegedly a "quiz show champion") appears in every episode of the quiz show, QI (2003). A running gag on the show is Davies' frequent last-place finishes.
One of the quiz questions involves the Al Jolson song "Avalon," which was involved in a lawsuit by Puccini because it resembled part of his aria "E lucevan le stelle" from "Tosca." This could allude to the similarity of the Inspector Lewis series theme to the song "Avalon." In fact, if you raise notes 2-4 of the Lewis theme by one note, the first phrase of the theme is transformed into the first phrase of "Avalon".