@[email protected] I worked in desktop publishing for a while in a large bank in the UK, producing things like product leftlets and terms and conditions sheets (exciting, I know).
The bank and a printing company jointly paid one contract night security guard a significant amount of money as a thank you after he happened to spot at the beginning of his shift that one of the pages of a 70+ page full colour brouchure was upside down, an error missed by the people at both the bank and the print house. All because he got bored enough to flick through the test print left lying around before the overnight run started.