It works and it's safe, so all's good.
Non sequitor.
Maybe you're just used to seeing the great work which most professionals carry out that when something falls below that standard you wrongly assume it is not acceptable. This is not the case.
Acceptable is not the same as good.
If you went to a restaurant for a meal, and the food wasn't so bad you couldn't eat it, it didn't make you ill, the service was acceptable, but there was nothing actually enjoyable about any part of the experience, would that be all you needed to say to your friends "you should go there, the food is good"?
Forget for a moment anything to do with the Wiring Regulations - if you were standing there commenting on the work, would the phrase "Yes - he did a good job there", or "Yup, that is good work" etc, pass your lips?
Would you
really use the word 'good'?
If you had an apprentice, and he presented you with that, would you
really say to him "Good job, lad"?
If a child of yours just scraped a pass in some exams, would you say "he got good results"?
The work isn't brilliant, but it isn't dreadful or none compliant. It's somewhere in the middle. What's that word between dreadful and brilliant?
Oh yeah. Good.
The very first entry for "good" in my dictionary reads:
having admirable, pleasing, superior, or positive qualities; not negative, bad or mediocre.
I take it that you're now going to start disagreeing with the publishers of the dictionary?