im sure he will Ze at the start everytime now. he was a litle puzzled lol. goes to show that the apprenticeships arent long enough these days and qualifications will never replace experience
He should have done an EICR on the installation before changing the board. Then the Ze would have shown up (like on the first test) and he could have got it sorted before it got critical.
Now he'll have to come back again and do all those live tests, otherwise he won't be able to give you an Installation Certificate!