That's because it's not offered as evidence. As you said, it's an anecdote. I've observed this pattern so often because schoolkids offer masses of kids. Every store had this same problem. I personally found it fascinating, but then, it wasn't my money.

I observed it from the other end. There was a group of kids who got together and stole from the neighborhood 7-11 and then everyone got punished with regulations like “no more than 2 kids at a time in the store” because the stores just thought in terms of “it’s always the kids stealing” and not “I’m not prepared to handle an influx of customers some of whom suffer bad impulse control”. Such a policy was problematic for us because the 7-11 was a 15-20 minute walk which meant that trip was the bulk of the lunch hour.

Are adults who slack off on the clock lie-cheat-steal machines? It seems like adults are far worse and do it far more frequently than teens then.