Back in 2020, Sir Sam Mendes released his World War 1 epic 1917 in the UK. The Oscar-winning movie, nominated for 10 Academy Awards, follows two British soldiers (led by George MacKay) on a mission to deliver a message to call off an attack the Germans were prepared for.

Featuring cameos from stars like Mark Strong, Andrew Scott, Richard Madden, Colin Firth and Benedict Cumberbatch, the film was shot in a distinctly unique way.

Acclaimed cinematographer Roger Deakins filmed the movie in long takes, making the two-hour spectacle look like two continuous shots.

Now, the British war classic is on TV tonight, but can you guess which cameo star made the most mistakes out of the entire cast combined?

Around 1917’s release, Express.co.uk attended the film’s press conference at the Imperial War Museum, where Mendes made the reveal.

Sherlock and Fleabag star Andrew Scott was guilty of making the most mistakes, meaning they had to go back and start the long take over and over again. Scott played Lieutenant Leslie in the British trench at the beginning who gives Schofield and Blake directions across No Man’s Land to the original German front.

Mendes said: “I’d say Andrew in his only scene made more mistakes than the rest of the cast put together!” But what was the cause of the trip-ups? Well, it turns out that Scott’s Leslie was having trouble with his cigarette lighter. Scott, who also played C in Mendes’ Spectre, replied: “Never smoke, never smoke in anything! On stage or in film. Never use a cigarette lighter.”

Mendes teased back: “He had a lot of props in that scene. Y’know, he’s not been acting for very long!”

The director went on to describe the challenge of shooting 1917 as one continuous shot.

Mendes, who is soon to be directing four back-to-back Beatles biopics, said: “You can have seven minutes of magic and then if someone trips or a lighter doesn’t work or they just do something normal like they forget half a line, you’ve got to start again and none of it is usable. We did seesaw between thinking, ‘Why are we doing this to ourselves?’ and thinking ‘This is the only way to work’. It was all the first until it was the second and the feeling…was so great when we got it that we wanted to do it again. There were some really tough days.”

1917 is on BBC Two at 10:30pm and will be streaming on BBC iPlayer afterwards for a limited time only.