After Rosie pulls the McAfee family out of the audience at The Ed Sullivan Show (1948), two different shots of the Russian conductor show the McAfees still sitting in the audience.
When Rosie pulls the Shriners under the table, she comes up wearing all their hats, but they still have their hats on when they emerge.
When Rosie originally confronts the Shriners, she twirls her shawl and tangles her hands in the ends. Viewed from the side, her hands are untangled and the shawl hangs freely at her sides.
After singing the final line of "One Boy," Rosie sits down on the balcony steps and wraps her arms around a support post. As the camera pulls away near a tree branch, the film cuts to a different take and Rosie's hands aren't in the same position as they were a split second before.
As the tortoise is placed on the rocking chair, the chair begin to rock slightly. A moment later, the chair is motionless.
Birdie has never been pronounced "bird-he" as Ann Margret does every single time in her song.
During Birdie's rehearsal in the gym he and his band are shown playing electric guitars, but the soundtrack features only one acoustic guitar.
The sheet music prop for "Mumbo Jumbo Gooey Gumbo" that Albert holds in the first scene is printed incorrectly. The title page is actually on the back of the booklet instead of the front.
In the long pan shot of the town square after Birdie sings "Honestly Sincere," a single "fainted" dancer sits up to see if the shot is over and then quickly flops back down again.
The turtle that zooms off a table and out a door is clearly a prop mounted on top of a dolly several inches thick that holds the turtle above the table and floor. The prop must have wheels as it slides so smoothly across the floor.
There are no wires from either Conrad's Fender guitar or the other guitarists.
When the turtle accelerates up some steps and out of an open door, you can see a clear ramp over the steps that allowed the turtle prop to slide cleanly up and out.
After Albert gives the pet turtle the initial version of the "Speed-Up" drug and the turtle speeds across the floor, then up the steps to the front door, reflections of the teens entering the door can be seen in the glass plate that they used to allow the turtle to get up the stairs.
Following the song "One Boy" Hugo tells Kim he has homework to do. As the camera pulls back the shadow of the boom mic can be seen on the ground.
At age 33 Jesse Pearson (Conrad Birdie) is about ten years too old to be have been drafted into the army at this time; at age 22, Ann-Margret (Kim McAfee) is the right age for a college senior, but four years too old for a high school senior; Dick Van Dyke was born the same year as Maureen Stapleton, who plays his mother.
Kim McAfee is described as a teenager, but Ann-Margret was 22 years old when she played this role and looks nothing like a teenager.