The wall became live only as far as the dampness spread, consequently it is very unlikely that an IR test would reveal the problem, unfortunately the customer completed the circuit on contact with the wall as they bridged to some other earthed area. Such things happen and I have experienced it a few times. As someone has pierced his cables it is hardly the electricians fault he wasn't even there. In my case it was similar to this the builder just nailed in the wrong place even without moving the capping, just a simple error, we didn't make a fuss about it when it happened on our work, though fortunately our trips operated. Human error occurs, tiredness, trying to complete as quickly as possible many things, builders, like the rest of us don't make mistakes on purpose but we are all human. How would it have gone down if he had insisted the electrician be called back to fit it properly? I was always grateful for the help I got from builders making our job easier.
