I dont think that i am god! And yes i am an NVQ Assessor. I do my job properly, and assess against the standards that are required. Anyone doing an NVQ can use a whole variety of assessment methods, it is up to the candidate to decide what and how they will gather evidence, the assessor should advise on how is the best way to use the evidence towards the qualification. The possible ways of gathering evidence is almost limitless, and as long as it can be proved one way or another that is authentic, then it is acceptable for inclusion. All you have to do to complete an NVQ is provide knowledge, by answering knowledge questions, and show evidence of performance by meeting the assessment route summaries by the most convenient way possible.
As for your assessor not seeing a cable dangling down, i agree he gave you bad info, but he is not there to assess the condition or faults within the installation, he is there to assess you.
Dont tar us all with the same brush, i dare say you are not perfect either, i know i aren't.
Cheers............Howard