I think from the comments there’s a radically different approach to responsibilities on this over the pond.
Re: correcting their work, ditto. Was fuming a month ago when I discovered two rings connected to the same socket - and managed to fit the two way dimmer (single common on a dual gang) he’d said was impossible. Think he only knew of one by-rote way to do a two-way, and didn’t actually understand what he was doing. Hell, he thought the US uses DC power - I explained that it was just a different voltage, and AC, and the look on his face said “voltage?”, so I left it at that.
He didn’t even notice I’d rewired when he came back to sign off “his” work.
OTOH there are incompetents in all fields - just that electricity is a pretty bad thing to be incompetent at if it’s your job - I learned a healthy respect for the tingly stuff the hard way.
Oh, and I was recently in Uruguay, where nobody seems to understand what the funny green and yellow wire is for, and hook it up to live. Metal skinned laptop. Funky chicken.