When Lisa opens "On the Origin of Species" to read to her fellow students, she starts "Chapter 1" but the pages are clearly open in the middle of the book.
Lip sync error: When Flanders says "As sure as I am that Jesus hates hip hop." The second half of this dialogue doesn't match up with the motion of his lips.
Lisa claims the creationist video Skinner and Hoover showed her class was slander. Since the allegations were made on video, it would technically be regarded as libel.