Drilled hole through a cable inside a wall

This week we went to a job where the customer wanted a new consumer unit and a new garage supply as the original garage supply had been wired in 2.5mm twin and earth internal cable, clipped to the outside brickwork of the house!

Quick, simple, easy job? Maybe, maybe not. See the picture I took.

Without boring you with the in’s and out’s of how we found this fault or how long it took ( 4 hours ) ! We found this piece of ring main cable that was badly burnt and damaged in a wall. It had obviously been drilled into.
I am sure we have all at some time drilled into a cable in a wall, but when the fuse blows it is a little obvious what we had done!

Did we just replace the fuse, refill the hole and redecorate the hole in the wall?

I am hoping and guessing that most of us would repair it or get a professional electrician to repair the problem before covering in up, Although it seems not everyone!