They do fail to answer your question quickly but the only examples I've seen have been very unique situations. I believe one member on this board had his fail when it sucked a bolt up.
The one in my car failed after almost 170,000 miles and after the po drove the car with alot of coolant in the oil. You can always have someone check to see what oil pressure is being produced. But you are correct that the design should not fail under normal conditions.
If your doing a rebuild you'd be better off taking a look at the timing components.