Nigel Green committed suicide after production. It had already been decided that his dialogue should be replaced by that of another actor in the finished film, Graham Crowden.

Alastair cast himself in the role as the Bishop, according to the commentary on the DVD. Alastair called up his friend Peter O'Toole, out of the blue, and told him that of course he'd help him by taking the part. No one was about to turn down the offer of such a great character actor, no matter how eccentric.

Alistair modeled his characterization of Bishop Lampton on the then-reigning Archibishop of Canterbury, the Primate of All England (chief religious figure in the Church of England), Arthur Michael Ramsey (subsequently Baron Ramsey of Canterbury). Portraits of Ramsey in the National Gallery show that he bears a physical likeness to Alastair.

There are two DVD editions of this film, but the Momentum DVD (though more easily available and cheap in the UK), is of poor quality, panned & scanned to 4:3, has low sound quality and, worst of all, only runs to 124 minutes despite the cover claiming it is full-length (154 minutes) and full-frame. Stick with the Criterion edition.