I'm surprised your surprised - given the nature of the responses the OP has given and the usual my friend the electrician is , out of town, on holiday, too busy, unavailable on the telephone etc etc - and I don't want to bother him until I know all the facts - then I will just get him to sign it of - Part P, Building Regs, notification absolutely no problem....... eh what are they?
Nevermind the lack of any certificates or evidence of testing from the 'alleged' rewire 5 years ago put further into doubt by the rainbow of colours in his CU.
While I am more than happy to help any diyer with electrical problems, that help stops abruptly when the less than competent diyer starts messing with contents of the CU especially, as in this case, when there is the lack of response to the question, how did you 'turn the electric off'?
Aw - maybe he's just a bloke who wants to wire some sockets into an existing circuit. Maybe he figured out that if he came here direct and said he wanted to open his CU, he would be flayed alive. Maybe when he says 'electric' he means 'electricity'. Come on guys, it's like the Spanish Inquisition in here. No wonder some people lie. Surely the worst thing is when they get so frustrated with the 'advice' that they move away from the forum and simply crack on blind.
Now - as has been said - I do think it's a touch pointless to open the CU, don't know why he has done it but, there we are, may as well stop him doing something silly now he's in there.
And hell, maybe he has got a very busy electrician mate.