In the final concert when Alan M. shows up and Josie is talking to him, she steps away from the microphone but her voice is still amplified as if she was still talking into the microphone.
After introducing everyone in the beginning there is a scene in the kitchen, Alexandra is seen in the background holding Dujour tickets but between takes the tickets re-appear and disappear again.
When Wyatt and Fiona are watching the girls at the big party, their monitor starts out with no text. The shot cuts to Wyatt and Fiona talking, then back to the monitor which now has the surveillance camera's location along the bottom.
During J&P's big concert at the end of the film, some of the kids in the live audience are also seen in other locations, watching the show on television.
When Josie, Mel and Val are taken to the salon to get facials and other stuff done Mel is wearing yellowish eye shadow, then the salon people put pink eye shadow on her. It alternates between yellow and pink in subsequent shots.
During the presentation to the investors/government folks, one woman mentions how much how much she loves Leif Garrett in a foreign language, which is subtitled. In the subtitle for what she says, his name is spelled "Lief".
When the band plays "3 small words" for the first time in the studio, the only one singing is Josie (Valerie's lips are moving but cannot be heard), but when Wyatt plays it back on the Megasound 8000, backup singing is heard. The Megasound 8000 is explained to be improving their singing and music, so this was likely added in by the machine.
In the concert in the final scene, Josie's actions in the screen behind her do not match her actual actions. This may have been from an extra take, as it does not appear merely delayed.
When Josie is playing the guitar in her room, in the mirror under the arm that's strumming, Alan M. is standing behind her.
The Chief, a fictional former member of The Captain & Tennille, says that he was mostly responsible for "Love Will Keep Us Together". However, Neil Sedaka and Howard Greenfield wrote the song in 1973. The Captain and Tenille's 1975 version was simply a cover.