Character mistake: The computer technician sitting at Megan's desk is "scoping" (her software is in "scoping mode"!) the GIFs the kids have been using to exchange information. Telling Cross what the name means, she says it stands for "Graphics Interchange Formats", while it is Graphics Interchange Format, no S. She also talks about "billions of 0s and 1s" making each image, which would mean billions of bits, which would mean the kids are casually exchanging 100 MB gifs, which are not so likely nowadays, and even less in 2001. (00:31:55)
Character mistake: Cross knows (for some reason) by memory the last words of the Lindbergh kid kidnapper (and killer) and that Soneji/Mercusio referenced in a book he finds in amazingly oblique ways. He calls him "Richard Bruno Hauptmann", while his name was actually Bruno Richard Hauptmann. (00:42:30)
Character mistake: Amongst the material collected about Cross in Jezzie's computer, there's a big magazine article related to the case of the previous movie "Kiss the Girls." The article writes in a huge font the title "The CASSANOVA killer." Not a very good magazine, misspelling Casanova like that. Incidentally, her notes also get the word "Temperament" wrong, missing the 'a', and she has a folder called "Dimitiri", getting the name of the Russian kid wrong. (01:28:30)