If you're running down the interstate and that belt was to snap off it would destroy that engine before you had time to react.
Engines don't grind to a halt the instant they lose oil pressure -- plenty of torture videos on YouTube to prove that. Besides, don't most engines run without oil pressure after an empty oil filter is installed? A thin film of oil on engine parts keeps things moving until oil pressure returns.Belt driven oil pump ... hummm, snapped belt, bye-bye motor. If it's out in the open like the service manual shows, then easy inspection and changing would be a plus.
When oil pressure is lost, a warning light appears on the dash. If there's an oil pressure gauge, it shows a problem. I'd imagine some models even have a warning chime / sound but not 100% sure. Point being, low or no oil pressure does not equal instant destruction unless you are pushing the engine super hard at the moment. Even then, I would bet that the engine keeps running for a little while before it grenades. So a driver would have to be completely oblivious (or distracted Haha) if they lost oil pressure and kept driving long enough to blow the engine.