Other mistake: In the book Hazel is reading near the start of the film, the word 'to' is used 4 times in a row.
Other mistake: At the end of the movie, when Hazel is reading the letter given to her by Van Houten that Gus wrote, Gus' voice-over says "I think we'd make a good team", but on the paper that sentence just reads "We'd make a good team."