Finding no cpc and either situation is pretty clear - non compliance and code.
The hang up (and penny just dropped, or maybe light-bulb moment ...groan...) is normally in our day to day work we wouldn't wilfully create a C3. And that is what we'd be doing.
I won't go on like a stuck record but I am genuinely interested in one point.
@Pretty Mouth I agree with number 3 as you have stated it.
I do note that both 415.1.2 which you quote and 412.1.2 have the word "sole" in them.
No argument at all from me that an RCD cannot replace any protective measure. That wasn't my point.
412.1.2 which is held up as the "you can't do this" reg (another £5 sorry!) talks about double or reinforced insulation as the sole means of protection.
Is it any sort of argument that with an RCD the double or reinforced insulation isn't the sole means of protection as there is additional protection. If so 412.1.2 wouldn't apply. I'll get my coat....