No, installing a cable and an accessory might be quite simple to a competent person. But testing that circuit, interpreting and understanding the results, what they mean and why they are required, requires training and experience. If an electrician makes a mistake then usually that fault is found during the inspect & test and can be rectified before the circuit goes into service. Therefore it is very extremely unlikely a fully qualified experienced electrician will put into service a potentially dangerous electrical installation.The same applies to if an electrician gets it wrong, then they cause a fire or kill someone. Like I said it is not difficult to understand, it is very hard to get it wrong. Everything is standardised, all the hard work has been done for us and is all there for everyone to read in the on site guide!
Being a qualified electrician means more than just following the onsite guide to install a cable!