Deliberate mistake: When all the thumbs are at the wall saying "I'm the king of the globe" and "I'm a dentist" you cannot see their legs, so that saved some costume work.
Thumbtanic (2002)
1 deliberate mistake - chronological order
Directed by: Todd Portugal
Starring: Rob Paulsen, Steve Oedekerk, Mary Jo Keenen, Paul Greenberg
Revealing mistake: When the old lady falls off her chair, you can see the wire pulling her off. (00:03:35)