I've never come across this before?!

[D Skelton]

She sounds more consiencious than alot of landlord/ladies !!

So true! Yes, she's a very nice lady. It's only the flat downstairs that they rent out so not a career landlord.

 

[Marvo]

I would think if the box has been cut to accommodate the pipe elbow then the IP rating of the box has been compromised or lowered. According to my local regs this would be non-compliant but I'm not sure what the UK regs say.
In the real world I would usually just apply common sense.