Several times I pointed out to the cashiers their mistakes in the supermarkets that were in my favor. Well it happens - instead of three packs broke two, or missed something at all, and I watch the actions and see it. So they look at the enemy of the people, not to mention to say thank you. I wondered why, but did not find out exactly. I think the whole thing is that just a missed not too expensive thing does not threaten the cashier with anything, especially because I will leave and nobody will notice what happened, and will not find out. And if some unusual movement begins around the purchase, there is a chance to attract the attention of managers, or the security, or who else is watching them there, and then the cashier can get a hole, they are not happy.
Can anyone confirm or disprove this theory?