Dickie is not wearing his gloves while he is making fun of Sam's bullies. It is not until several minutes later in the movie that Gracy Finney convinces him to get rid of his gloves permanently.
When Dickie is taking pictures in his pants, he moves the camera around but the flash does not move.
When Rob Reiner is driving out of the parking lot before he gets attacked, the passenger-side window is down. Moments later, it is up.
At the end of Heather Bolan's audition, her hands are in her hair. She is shown from behind, and she puts her arms down. When she is shown from the front, she puts her arms down again.
When Grace puts the cereal box in front of Dickie, she puts it where he would get it with his left hand. When he gets the cereal box, it's placed where he picks it up with his right hand.
When Dickie is getting into the silver Honda Insight, you can see a crew member holding a "bounce card" reflected in the door as it is closed.
Grace Finney gets mad at Dickie for saying "crap" at the dinner table, yet minutes later she is fine with Sally saying that the tree house is "old and crappy".
Leif Garrett tells Dickie that Reiner's new movie would be similar to when Frank Sinatra had a film career comeback and won the Oscar for From Here to Eternity (1953). When Sinatra did "From Here to Eternity" his acting career was still pretty fresh and did not do many films in the years prior. So, although his Oscar win was highly impressive, it was not a career revival.