One of my friends works at Costco. He says that before the holidays they sell a lot of furniture and after the holidays they see a lot of furniture returns.
It's more the depreciation and how quickly electronics evolve. People were using the returns as a free lifetime of upgrades.
One particularly stark example when I worked there a long time ago was someone who wanted to upgrade their old projection TV.
So four years after they bought it they brought it in and returned it. They got about $4k back. They walked out on the floor, picked up a brand new LCD TV for $2k and almost half a decade after their original purchase they walked out with a brand new, upgraded TV and $2k in their pocket.
You can imagine how this can be abused with most electronics that Costco sells. Imagine going in and getting a brand new upgraded laptop every 2-3 years for the rest of your life after a single couple thousand dollar purchase.
I saw someone return a flat of steaks with half a remaining cooked steak left just saying "my guests thought they weren't very good".
Someone had a custom photo book printed and when they came to pick it up decided they didn't want it anymore and just got a refund.
Someone returned a plasma TV because of the glare from their windows.
My wife bought a car seat there (something you can't return _anywhere_) which we ended up not being able to get installed in the car (had the shitty cheap version of the LATCH clips that are impossible to get tightened up). Took it back for a full refund.
We bought a vacuum there that broke literally a week after the manufacturer's warranty. Brought it in and exchanged it for a new one.
There's no time limit on any of this.
This is by no means normal in North America. It's one of those Costco things like providing part time retail workers reasonable salaries and health benefits, etc that sounds insane in theory but obviously works for them.
I know personally there's been a couple times where I've been on the fence about buying something and ended up purchasing it because "If it sucks/falls apart in 6 months/whatever I can just bring it back."
Add to that the people who realize what a waste of an investment that was after the holiday spree is over, you can explain it a bit more.
But of course, it's impossible to tell surely without data.
Going back to gut feelings: Does he see suspicious behavior? Weird reasons for returning?
A couple random things - the first stack of shelves that face the front of the store are managed to give a good impression. They always keep those shelves full of pallets and try to have a lot of only a few items to give a clean look. If the warehouse has empty space they try to keep it so you can't see from the center of the store.
It's gonna be impossible to concretely discern intent from the data you could get, but it's pretty obvious there's _some_ abuse. The only question is where you draw the line on abuse and how much.
January at our store was a rush of returns of opened and used Christmas decorations because "I decided I don't want it anymore." Often times from people that had done the same thing year after year. We'll never know what those people really intended when they bought it in the fall, but you'd have to be pretty damn charitable to assume the best of intent in all the cases. Especially when it was people doing it multiple years in a row.
I assume it's some combination of degraded quality as most stuff is made in the same Asian factories and an increasingly widespread attitude that it's OK to take anything that isn't nailed down.