4.7 Evaluation of an expert opinion 

The competent department must examine whether the grounds on which an expert opinion is based are convincing. Notwithstanding its discretion in the evaluation of evidence, it may not disregard an expert opinion in the absence of grounds based on adequate specialist knowledge of its own or of another expert, irrespective of whether the latter expert is an independent expert commissioned under Rule 121 or an expert who testifies at the request of one of the parties.