Continuity mistake: Millie's beads have a mind of their own. They do not stay in place even when she is standing still. Besides the funny scene during the title credits (when it is deliberate), and when Miss Dorothy registers, they also move during a scene when Millie displays her thoughts on Miss Dorothy's beads when the two of them go into the elevator for the first time.
Revealing mistake: During the opening musical number, right before Gary joins the large group of people for the dance, he accidentally kicks Walter out of frame. Watch closely though. His foot comes nowhere near Walter when he supposedly "kicks" him.
Factual error: In the 19th Street Parade, it shows the Budweiser Clydesdales pulling their famous wagon. Even though this movie is set in 1897, Budweiser did not start using Clydesdales until April 1933 when the sons gave their father, August Busch Sr., the owner of Budweiser, a 6 team team of Clydesdales to celebrate the end of Prohibition.
Continuity mistake: At the end of the film the plane they are initially flying on is a typical passenger plane, but when the Muppets are thrown out, the plane is one used for skydiving.
Continuity mistake: When Otto is sat down at his HQ, telling the Vet and Kisko that they would become steak, Otto is holding the newspaper in his hands, but in the next shot, the newspaper has disappeared, and he stands up, holding the steak. (00:20:10)
Continuity mistake: Fiona Fullerton's eyebrows change from full to plucked and back again all through the film.
Continuity mistake: In the prosecuting attorney's speech in the first courtroom scene, the judge's house of cards is no more than 2 levels high (a base level with a peak) [0:2:20]. In the close-up shot of the judge, the house of cards changes to 3 levels high (2 base levels and a peak)[0:2:35]. When the scene focuses back on the prosecuting attorney, the house is back to two levels of height[0:2:39]. (00:02:20)
Visible crew/equipment: In the final musical number "Strictly off the Record", you can clearly see the shadow of the microphone boom during part of the number.
Continuity mistake: When Leona is telling CC that they will pack up and leave to go see her father, there is an orange shirt on the desk to her left. In the next shot, as she gets up, it has vanished, then it reappears when Hilary goes over there.
Other mistake: Towards the end when Janet, Brad, Oliver and Betty are singing "We're going to do it anyhow," as they are dancing down the aisle, Betty very visibly trips and grabs Oliver to stop from falling over.
Continuity mistake: Near the end of the movie, when Snow White has already been tied up by Lord Malice, the Dwarfelles come to rescue her. As the Dwarfelles are beating up Lord Malice, there's a quick shot of Snow White again and she is untied and has her hands covering her cheeks. Next shot, the fighting between the Dwarfelles and Lord Malice continues and Snow White is again tied up.
Other mistake: Marian asks Winthrop to go pick up a book called "The Indiana State Educational Journal 1901-1910". When we see her reading the book, it actually says "The Indiana State Educational Journal 1890-1910". (01:08:25 - 01:13:50)
Revealing mistake: In the scene where Rooster is driving/running away from the gangsters, he is supposed to be alone in his car but in one shot a hand appears and is holding on to the passenger side door from inside the car.
Continuity mistake: When JB talks to Ms. Jones on the intercom after talking to his wife on the telephone, he asks where the "You know" is. She says "It's in your top right-hand drawer." You can see him moving to his left.
Continuity mistake: Set in the 1930s, Steve Martin is teaching a class of grade-schoolers in one scene. This would only be picked up by Canadians, but one of the many flags on the wall is the new (as of 1965) Canadian Flag - Red Maple Leaf with two red panels on either edge.
Factual error: Before 1949, when the part of the film set in Hollywood takes place, the famous sign on the mountain read "Hollywoodland", not "Hollywood". The sign had been allowed to deteriorate and during that year, the Hollywood Chamber of Commerce offered to remove the last four letters and repair the rest.
Continuity mistake: In the scene before the king and servant story, the people throw a lot of junk on one of the followers. If you look closely, you can see the accordion used in the scene before piled on him twice.
Continuity mistake: In the childhood oven scene, there is a shot of the mother peeling steamed tomatoes, the shot of the tomato she throws at Hedwig shows fresh tomatoes, then the tomato looks steamed in the oven.
Continuity mistake: At Molly's party after returning from Europe, the Duchess is introduced, and everyone bows. The shot shows Molly reaching for her neighbor who's standing straight, to bow down, and she does. Then there is a long shot showing the crowd, and the neighbor is again standing, and then you see Molly reach out for her again as she just had.
Audio problem: In the "How Lucky Can You Get?" musical number, when Fanny is turning on the stage lights she is not singing, although Streisand's singing voice is heard on the soundtrack.