Annex 1 from 965/2012, definitions....
(72) ‘landplane’ means a fixed wing aircraft which is designed for taking off and landing on land and includes amphibians operated as landplanes;
(106) ‘seaplane’ means a fixed wing aircraft which is designed for taking off and landing on water and includes amphibians operated as seaplanes;
So it seems the examiner was not exactly telling the truth.