This thread seems to have wandered a little bit but the original post gave me a laugh.
Why not tell the client to get the kitchen fitter to point out in his electrical regs book the bit where it says the mortagage surveyor is gonna come in with an SDS drill and take all the plaster off his wall to check for capping and then fail his electrics.
Alternatively
If the chippy is smaller than you it might be more effective to just give him a well earned crack in the jaw.