The cable may only go into a neighbours house.
My house has TNS and 2 years ago I tested the earth after replacing some sockets and I recall it was 12 ohms, the Dno came out even fitted a new head and still the same, my supply links to next door to the Left and they too have the same High loop, (One single phase cable).
They went into two doors away to the right (single phase ) and apparently they have a 3 phase head, so I assume my house somehow connects to that, yet the earth there is ok, but the Dno reterminated the Earths in there anyway, when my floor was up, i recall seeing the cable laying there just like the Ops..
Two years later still not sorted, how hard is it to just thread new cables if needbe just under two houses, they said they need access to the house between and its my job to arrange it, which is hard as i dont even want to talk to them
, due to other issues with them in the past, but thats another matter.