Grading the students' papers, Miss Halsey marks Tristan's essay test as "Stupid point Misspelled" circling the word "layer" (which is lawyer without a W). However, she misses the more obviously misspelled word "lawer" (lawyer without a Y), and overlooks the use of "whose" instead of "who's".
When Ms. Squirrel eats the apple covered in poison ivy, she rubs it on her face which results in a rash where she rubbed it. However she would have also had this rash on her lips and mouth, but she does not.
Elizabeth is seen collecting cans from the school in order to pay for breast implants. Illinois does not have existing container deposit laws, however, Elizabeth could have earned money through selling the cans for their aluminum value to a recycling center.
At the beginning of the film, Elizabeth Halsey speeds backwards violently past a school bus and makes a sharp turn leaving visible tire marks on the ground. You can see tire marks on the ground before she creates them and were probably created in previous takes.