It's the mother talking also.

As parents, we're all teachers to our children.
I'll never forget the look on my son's face when I went back around to the Taco Bell drive through to return the near $40.00 extra change that the cashier gave me. When I counted it, my son had this huge Christmas morning grin...and when I pulled back in..he was dumbfounded. I told him, it wasn't ours to keep. That the cashier might loose her job..and someday he might have a job where he might loose it if he made such a mistake.
I think you're right..what are they teaching their kids by doing something like that? Seems so petty and small, and not a big deal. Only kids watch every little thing. They don't stay little forever..and it would be nice if they turned out to be decent human beings, and you know as a parent that you had just a little something to do with that.