Have you ever spotted this mistake in The Sound of Music?
American-born actor Nicholas Hammond appeared on Rove’s new program Show Me The Movie! and was left stumped after one question from the host.
Hammond, who played the eldest son Friedrich von Trapp, and the other panellists were shown a clip from the iconic musical when the von Trapp children performed “So Long Farewell”.
Rove asked the panellists if they could spot the continuity error that appeared in the scene.
Hammond, who might've been blinded by his memories of shooting the scene, couldn’t give the correct answer.
“So no pressure... you were in this scene Nicholas Hammond from The Sound of Music,” Rove said.
“The mistake is obvious... the mistake is my dancing,” Hammond laughed.
When Rove went to the rival team to see if they could give an answer, captain Joel Creasey confessed that two of the teammates had never watched the movie.
“Leave the room!” Hammond joked, causing the audience to break out in laughter.
After the contestants failed to spot it, Rove revealed that the mistake was with the von Trapp children’s choreography.
The children were seen several feet away from the end of the carpet at one point but then seconds later they are standing at the very edge.
Hammond was only 15 when he starred in the movie alongside Julie Andrews.
He later starred in the Amazing Spider-man '70s CBS series and has not yet retired from acting.
In the last few years he has appeared in several productions and has a role in upcoming Australian show Ladies in Black.
He now lives with his partner Robyn Nevin in Southern Highlands, south of Sydney.
Did you ever spot this mistake in The Sound of Music? Let us know in the comments below.