A landmark contract in May this year pushed top-of-the-scale pay for United Airlines flight attendants to $100.13 per hour for experienced crew by the end of the five-year contract. In addition, they added boarding and sit pay and included a signing bonus pool of close to $740 million, according to CNBC, sharply raising the cost of every pay-protected trip. So why did United, after just a few months, have to start policing its own flight attendants?