Revealing mistake: When Haru looks through the phone-book, you can see they took a real phone-book and simply glued a strip of paper that had 10 rows of fake names and numbers over a section of it (leaving space to make "Tanley, Martin" stand out). You can also see the name are briefly out of alphabetical order because of this. (And anything seen that is not covered by the strip of paper is a real person's actual address and phone number).
Revealing mistake: When Haru changes clothes to his pimp outfit in the store, Joey waits outside. If you watch closely while Joey's waiting, you can see the scene "jump", showing that it was two different shots spliced together to give the illusion that Haru changed in a couple of seconds.