Way, way, way, back in the day, I worked at Home Depot. Back when it was privately owned still. I would work the returns desk from time to time and people would come up with all kinds of defect excuses when in reality all they had to say was they didnt want it. Back then the return policy was very lenient. Because it was a return and was listed as defective, we couldnt sell it as new and as said above; 95% of the time the item worked perfectly. There used to be some great deals on things that had phantom defects.
I picked up a used "defective" Honda lawnmower that was used maybe once for half price. I still have that lawnmower today and it has never skipped a beat.