EMS vs Surge vs nothing

Well, since that reflected hot skin condition requires two faults to occur simultaneously (an open ground in the campground's wiring, plus a ground fault current generated by a camper connected to the same power source), it seems to me that it would be more likely to encounter either one of these conditions alone.  In that case, our EMS would protect against the open ground.  And in the other case, wouldn't the ground fault trip the breaker?  Still, to cover all cases, it would be a good idea to routinely check the pedestal and the trailer chassis with a non-contact voltage tester that goes down to 40 or 50 volts or less.  And if an open ground is found, the campground needs to know this can put camper's lives at risk of being shocked by someone else's shorts!