The thing about human factors is clever people do stupid things. I suggested at the beginning of this thread, in a roundabout way, the pilot had turned the fuel off. It happens. Whether the system is "flawed" or not, it's self-evidently possible to make a mistake.
My understanding is the pumps can run dry for 30 minutes. If that is true, I would turn both on at the beginning of a flight and not touch them again. By my reckoning, when a pump would run dry for 30 minutes you don't have 30 minutes fuel left.
If you think yourself you're too smart to make a simple error you don't understand the problem.