Protective-Earthing the chassis with the earthing point being the star-point - How does it keep the Chassis at Earth potential?
The thing that is not being drawn in all the diagrams is the parasitic resistance and inductance. Wires have resistance (and even earth does also), so if there is any current it will generate a voltage, but not much if the ground wire is sufficiently large. 

If the ground cable is a few ohms, the amount of current the ground wire could support before a dangerous voltage 60V+ could build on the chassis would be about ~60A. The neutral wire would also take current away before you have much current on the ground wire in the event of a short\fault.

Not to mention that most systems like this would also have circuit protection like circuit breakers, so as soon as there is a short, the system shuts down.