Quote: billwill @ 18th September 2014, 1:31 PM BSTIf your main 'fuse' box in fact has RCD (residual current detectors) in it, he could indeed have "done it from here" by shorting the neutral (blue, new colour or black, old colour) to one of the earth wires. Not a desirable practice to to do though.
However though you saw something ON, he might have already turned off the lighting sub-circuit. He probably knew what he was doing, careless electriciand don't live long.
Ah, interesting. I asked him twice because it seemed so important. I think the "I've done it" was the first answer and "from here" was the second. I didn't quite get that second one as it was mumbled. I sensed a slight irritability about the question being asked again, not that he didn't seem decent and professional.
I felt he did know what he was doing by his approach to it. Thanks billwill for that additional information.