The chances of getting a faulty engine are near zero. The odds of an engine failure due to running it out of oil are much higher and I read this as a case of never raising the hood at all to check anything.
Those old enough may remember full serve stations when everything was checked no matter if a customer bought 1 dollar’s worth of gas or got a fillup.
The advent of self-serve/quick shop stores mean the engines seldom see daylight anymore and almost every premature engine or transmission failure is always traced back to negligence on the car owner.
I’m curious as to whether or not the oil filter notation was also written on the customer receipt.
Since it was low then odds are the engine was damaged goods to some extent at 24k miles and the last 6k miles simply put it out of it’s misery.