The bad secret behind is - EU is no 'state' and ICAO requires all Part.FCL PPL administration to be done by the state issuing. Yes, they stamped EASA on top, but it is still national licensing.
If that guy permanently moved to Norway, there are two ways. Either arrange with a fellow examiner to get listed as UK examiner (could make sense if more pilots around in need of a UK checkride) or transfer the license to Norway CAA (check requirements before, i.e. data protection and medical handling before to decide feasibility).