I'm with Trev on the something smells fishy about this. It's just too close a time scale and too convenient. Has someone been watching Corry a little too closely??
It stands to reason that if an installation has been verified as being electrically safe, twice, then it IS electrically safe. If IR tests were done, and connections tight, with next to no load at 1am - where's the energy, where's the heat?
£55 per week - well, it's more than possible. Shower, washing machine, dishwasher....
I always take photos before, during and after all my inspections and final sign-offs on new work, for just this reason.