Many years ago, a bar owner shared with me the tale of how he was losing so much money in one of his bars he had to hire a loss prevention specialist to pose as a customer and watch his staff for any signs of financial impropriety.
The undercover customer spent nearly a month visiting the bar (what a job!) and reported back that he found nothing was amiss. He said he watched all the cash registers for four weeks and didn’t see one suspicious transaction at any one of the four registers.