It's a story like this that really lends itself to the whole belief that many people can definitely benefit from working customer service jobs. When you're forced to grind through shifts in a hellish, steamy, downright frantic dish pit where it feels like time itself is moving along like it's wearing ankle weights, you can develop a whole lot of empathy for anyone else who has to work the same job. Or, if you end up working the floor and dealing with unfortunate waves of unruly customers, the same principle applies.
The hope would be that people wouldn't need to suffer through those jobs to be reasonably mindful when it comes to respecting people working customer service jobs, but it's glaringly evident that that is not the case. So, when this customer was caught red-handed for trying to pawn off a straight up fake tip to a hard working waitress, their whole game was exposed. Seems like the appropriate move. Could the kid have approached the conversation with their mom a bit more gently? Sure, but otherwise they weren't in the wrong.