I agree, this is the most likely scenario.

Regarding placement; this is a debated topic with proponents on both sides.

If the shut-off valve is before fuel pump you can shut off the fuel source to the pump in case of a "wide open" run of the pump (yes I have seen this once when an ECU 'fried' during a start). If the shut-off valve is after the pump, the fuel pump still has a supply of fuel in such an event. I agree, this is such an unlikely occurrence, but nonetheless plausible. I personally place the valve before the pump if at all possible, but I'm sure other people's mileage will vary.

You may get the other view point shortly.

George