Factual error: "Venus" by Bananarama is playing when Brian gets home for Christmas. The song was released mid spring 1986, but the movie takes place in 1985.
Factual error: During the "University Challenge" competition: Brian answers a question with "Calcium Sulphite" and the question-master says he gave the correct answer of "Calcium Sulphate" (a different compound).
Character mistake: Lucy says the source of the quote "To err is human" as Alexander Pope's "An Essay on Man." The quote actually originates from Pope's earlier work, "An Essay on Criticism."
