Question:
Isn't the authorisation of Examiners down to the Competent Authority?
Therefore it is the Competent Authority's interpretation of Part-FCL which is important and they who can decide who and how can test whom and for what.
I agree with all the replies so far; but that is because I am UK based whereas the OP is in Iceland. Does the Icelandic CAA have the same interpretations as the UK CAA?