Worse one I've seen; my Father in Law is changing his oil, the new oil came from Wal-Mart. He opens the oil and realizes that someone put their old oil in the containers and returned them.
I do this on every oil change. I put the old oil in the original container and return it to Wal-Mart. Wal-Mart takes your old oil for disposal for free. They just limit you to 3 gallons per day. I can easily see how someone could see a new looking container sitting on the floor by the desk and returned it to the shelf without checking it. That's on Wal-Mart...not someone returning used oil for a refund.
