Character mistake: When Bob Munro (Robin Williams) is behind the tractor, the speedometer shows that it is below 10mph. He then states that they are going twelve. How could he if they didn't reach 10mph yet?
Character mistake: At the end of the movie, Darryl tells Calvin they don't have a back door. There's a back door in the kitchen and another door that goes back to the backyard patio.
Character mistake: When Gwen Piper is talking to Aggie in the soup pot at the beginning of the movie, Aggie addresses Gwen as Linda.
Suggested correction: Aggie says Gwen darling.
Character mistake: When Cruise goes to see if the Champ is OK, he says his boss bet all the money on the race. It was not his boss who bet the money, it was Lugnut who bet the money. (00:25:10)