Definitely appears gold plating. Surely an FAA to EASA candidate who is current and flying regularly IFR/Airways in Europe, by definition,is obviously fit for test. Also I can't see why aircraft type used for the Test is a factor, as the candidate can be P1,he is exercising his FAA qualification during the EASA conversion. Therefore no requirement for the Examiner to be qualified on type either.
I doubt though if common sense will prevail.