How does grounding prevent electric shock?
Given the impedance of the live and the ground return path are roughly identical, a person touching the case during the ground fault will face half the live voltage. That's already much better than full live voltage. You could provide a thick ground return path to drop this voltage even lower.







simulate this circuit &ndash; Schematic created using CircuitLab

But yes, the protective effect comes from the fuse on the live wire blowing due to the short circuit.