I used to install systems, and I cant understand why the fuk he's drilled from the outside inwards.
We allways drilled from inside the house outwards...
That said... Once I was up in a gable end of a house fitting a dish, and it had been stone clad then painted. All I remember is a loud bang and a big flash, the next thing I knew I was hanging upside down from the ladder, a hole in the wall the size of a dart board and the entire village with no power... Fukkin stupid place to put the mains cable to the house
It had also completley melted the drill bit