How does O'Reillys determine you are not pulling a scam saying you were sold used oil when it was you that poured your new oil in your car, filled the just with used oil and went back to O'Reillys to complain.
Not suggesting you did. But O'Reillys might think so.
I, too, fell for this at Wal-Mart several years ago. They straight-up accused me of fraud and denied my return. Had to go through corporate to get my money back.....
Don't assume the cap ring being intact is 100% foolproof, either. There's a way to get that cap on the bottle in the factory without breaking anything. The paranoid among us should probably hold the jug up to the light, when applicable in design.
Going a little into policy here, but if someone was caught doing this, there should be substantial consequences. A hefty financial fee and some sort of public tarring event. Let others know, if you get caught, this happens to you.
imagine Chris Hansen, but with Motor Oil. Bob is the oil thief catcher guy.
This got me thinking of other auto fluids that would be worse. If I started to pour a jug of used motor oil into the engine I could just easily drain it out. No rear harm done.
But how about something you don't see in a funnel like DEF fluid? Someone filled the jug with water and returned it? Even if you somehow figured out it was water there isn't an easy drain plug like the oil drain plug.
As someone else mentioned, I firmly believe not all but most of these used oil incidents are where people legitimately returned used oil to the store intending it to be recycled and some unsuspecting clerk interpreted it as a regular return and simply put it back on the shelf.