Kind Hearts and Coronets

Sir Alec Guinness nearly drowned in the scene where the Admiral goes down with his sinking ship. Guinness was held down by wires whilst the set filled up with water. Once the scene was wrapped, the crew started to leave, until one technician suddenly realized that they had forgotten to release Sir Alec from the wires holding him underwater. He immediately dove into the waters with some wire-cutters and freed Guinness. Fortunately for all concerned, Guinness took great pride in his ability to hold his breath for long periods of time.

Initially, Sir Alec Guinness was only offered four of the roles. It was Guinness who insisted on playing all eight.

Agatha's death in the movie caused some consternation for Sir Alec Guinness. The scene in question, a hot air ballooning accident filmed in a field next door to Pinewood Studios, prompted him to ask the producers if he was well insured. They told him that he was, to the tune of ten thousand pounds sterling, but Guinness didn't think that was enough. He then declared that the balloon could not be raised any more than fifteen feet unless they raised the insurance to fifty thousand pounds sterling. Ealing Studios was renowned for being very penny-pinching, and it naturally refused Guinness' demand, pointing out that he would be accompanied in the balloon by a well-qualified Belgian balloonist hidden in the basket with him. Guinness was undeterred in his refusal to perform the stunt, so the scene in the finished movie is not him, but the Belgian balloonist wearing Agatha's dress and wig. Guinness had the last laugh, however, when a high wind pulled the balloon off course. The Belgian balloonist was found fifty miles away, having had to jump into a river.

In addition to the eight roles played by Sir Alec Guinness, a painting may be seen in the Duke's castle showing an ancestor, a painting for which Guinness sat.

An alternative ending was required for the U.S., where distributors balked at the movie's ambiguous ending (the U.S. Production Code at the time stipulated that crime could not be seen to pay). These extra ten seconds were not kept by Ealing, but were unearthed at the Museum of Modern Art in New York City, where they had been quietly filed away in a film storage facility.