OOH dear ladies!
There is no point having a dig at the Assessor. He has no control over B&Q selling things, he isnt a genius, he doesnt know all the answers, british standard have got nothing to do with him, scheme provider fees are not set by or charged by him, he will not get anywhere near £400 for his halfday visit. He is not there to pass or fail you, he wants to help and advise, he is knowledgeable about the subject he is assessing, you should also be knowledgeable about it too, or you wouldnt put yourself up for assessment.
An Assessor's job is to,
Assess that you are competent in the subject field. In this case he is assessing your ability to be able to work to a set standard as laid down by BS7671, and its implications with the building regulations. He is carrying out an Assessment of you, against a set criteria, which is the same criteria for all who are being assessed for the same purpose. The assessment should be fair, and all candidates should be assessed to the same requirements. If you are assessed as meeting the criteria, then you will be told so, and you will also be told if you do not meet the required standard.
The scheme provider assessors all hold the Qualification of Assessing competence in the workplace, and this is limited to assessing in their subject field.
You need to remember that the Assessor is an Electrical Engineer of some sort, and will have extensive subject knowledge, just like you. He wont know it all, and neither do you, but he wants to see that you can find out what you need to know.
I hold this qualification, but dont assess Part P Electricians, i deal with apprentices, but the practice and principles are exactly the same.
Cheers..........Howard
