The Capital City sign on the bus changes position in between shots.
Bart and Lisa's fanny packs disappear when they arrive at Capital City.
Bart and Lisa get into a fight before leaving Capital City and fall down a hill, they then fall into a river, with Bart on the right and Lisa on the left. The underwater shot shows that now Bart is on the left.
The Third Grade teacher is nowhere to be seen when the School Bus leaves Capital City for the second time.
Bart says William Jennings Bryan was an answer on the test, even though the Third Grade Teacher mentions it was a math test at the beginning of the scene.
When the grades go on the School Bus to Capital City, Otto says "Pukers in back", but his mouth his open and doesn't move.
When Willie is carving names into the field trip memorial, he says "Why is it always the kids with the long names?". One name says Judy and no surname which clearly isn't a long name.