These kinds of stories can be seen as low level cons. We like to think of con-men as running complex schemes, but it's all about building confidence. You can do it with a uniform, or just do it with an attitude.
A guy I worked with years ago (when we were in our 20's and broke all the time) ate for free at a local chain coffee shop for months. The first time was an accident: he ordered a fancy sandwich and iced-coffee drink, went to sit down and eat it, realized he hadn't paid and yet nobody said anything (there was a quirk in how the counter/cashier were situated.) So he did it again every day for months before they caught on (and then only made him pay for that one meal, though they probably suspected him of a lot more.) The fact that he ate in the store most of the time made it seem legit, so nobody thought twice.
At one of my old jobs this was referred to as "profit sharing."