As you've opened the world of fiction...
the dishwasher is on fire, so the husband tells the wife to walk over TO the fire, reach through the flames to switch off the appliance. Anyone who advises any non trained and non equiped fire fighter to move towards the fire is an idiot.
Plus I never knew that such switches acted as automatic fire extinguishing systems?
OK that's fiction in the fantasy world of some people.
Here's the REAL world of complying with the REAL Regs:-
If the socket outlet is behind the built-in appliance and is 'functionally' controlled by a DP switch above the work top, how is the fixed wiring installation going to be tested up to the last point (the socket)?
Answer, unless the built-in appliance is removed, it can't be. Therefore the Regs can NEVER ever be complied with unless the built-in appliance is removed.
So, if the 'functional' switch above the worktop controls a socket inside a cupboard, is there a point to having the switch above the worktop? Perhaps, for the sake of user convenience but NEVER because it's required by the Regs.