I worked in ski shops for years - both in the shop & on the sales floor. Yep, I had my fair share of toxic customers. But one in particular is really burned into my memory. I'd seen him in our store a few times, just browsing. He was (as I found out later) a Doctor of some kind & seemed very well-to-do.
One day, the guy came into the store with two of his teenage kids. He wanted to outfit himself & his kids with new ski gear & clothes. A ski salesman's dream. Things went well initially. But after over an hour of ski selection, boot fitting and clothing selection he started to get impatient. I then put up with a number of insults. The worst was him turning to one of his kids and saying loudly "See, this is why you need to go to college, otherwise you'll end up working in a place like this!". Sheesh. We had a great shop run by great people, so that particular comment stung. But he was springing for a big ticket sale, so I kept my cool & closed the sale.
Now here's the sweet part...
After ringing him out I watched the father & one of his kids head for the door. They had multiple bags of stuff they just bought. The second kid came from a side isle & met up with them on the way out. That kid had some bags (our store bags) of stuff too. When they got to the exit the theft alarms went off. To keep this short: nope, we didn't forget to remove a security tag. The father & kids had stuffed their pockets with stuff (e.g.: sun glasses, wax, even socks). Plus, one of the kids had used a big bag (presumably from a previous sale) to fill-up with 'merch while we were ringing-up Dad. They were totally busted. We detained them at the store (we had retired cops working at the store) & I watched the police take 'em away. While waiting for the police I asked the father why he would do such a thing. His reply amounted to "I spent so much money I though I deserved something extra". I do remember him saying over and over how he didn't think this was a big deal & that he'd gladly pay for everything. The owner thought otherwise. To this day I can't believe what an awful role model that father was to his kids that day. Just tragic.
Anyway, this happened in the late 70s (or early 80s). Back then, our store was an early adopter of this particular kind of anti-theft tech. We'd installed the tag & detector system just a few weeks before the guy tried to shoplift.
It was a bittersweet outcome: a jackass customer got what he deserved but I lost a huge sale. :^/