He may have changed it and you have a oil consumer.
Yes and in a few thousand miles you may know. Just watch the oil close. If its using oil and your relative didn't tell you that well just saying don't buy your next car there.
But just because you found a sticker from 2014 doesn't mean that was the last change some people don't use those stickers and those stickers can fall off. Now you have current documentation and you'll sort it out.
By the way did I miss it how miles does the car have on it?