The most likely danger with this fault is that someone would touch both the live device and ground, causing a path to ground. This would cause any RCD to trip.

The most likely danger with this fault is that someone would touch both the live device and ground, causing a path to ground. This would cause any RCD to trip. It's obvious that whoever owned this didn't have one installed because even the cable shorting to a grounded radiator didn't cause a trip.