On the advice of the director, Stephen Frears, Ben Whishaw met with the real Norman Scott during the course of the production to hear his account of the events.
Jeremy Thorpe died in 2014. The drama could not have been made during his lifetime for legal reasons. Thorpe could have brought a case of libel against it for portraying him as being behind the conspiracy to murder, given that he was acquitted in court and never even publicly acknowledged his homosexuality.
Jeremy Thorpe was the first British politician to be tried for conspiracy and incitement to murder. Although he was acquitted, the scandal finished his political career.