Whoever said that 'the customer is always right' clearly has never dealt with a customer in their life…
People in customer service positions have it harder than we are willing to admit. Daily, they come across people making ridiculous demands, showing disrespect for them and the place's rules, and who believe they have the right to tell anyone anything just because they are paying. Most of the time, employees have to stand there quietly, with a smile plastered on their faces and without giving any kind of answer. But other times, they are free to do as they please and give the people a taste of their own medicine. Those are the times when sarcasm and witty remarks really come in handy.
I know a thing or two about backhanded comments myself, and I have one or two stories. Years ago, one time when I was still a teenager, I was at a friend's house having dinner with a bunch of other kids. I was talking to my friends about something, don't remember exactly what about, when one of the other kids across the table started randomly smirking and laughing. Since he had interrupted me, I asked him politely, 'Hey, what's so funny? What are you laughing at?' And he, as a dumb teen that he was, didn't exactly want to tell me and just said, 'Nothing, I was just looking at (other guy's) face.' That day I wasn't feeling very forgiving, so while looking straight into his eyes and face, I answered, 'So, right now, I should be literally cracking up, right?' The whole table started laughing; the guy never caught on to my passive-aggressiveness.
Well, something along those lines happened to this girl working in customer service. The customer was being annoying and loud, and complaining about the establishment's policy. And she managed to make him call himself 'childish' without him even noticing.