50.—(1) Where an appeal tribunal require one or more experts to provide assistance to it in dealing with a question of fact of special difficulty under section 7(4), such an expert shall, if the chairman, or in the case of a tribunal with only one member, that member, so requests, attend at the hearing and give evidence and if the chairman or member sitting alone considers it appropriate, the expert shall enquire into and provide a written report on the question.
(2) A copy of any written report received from an expert in accordance with paragraph (1) shall be supplied to every party to the proceedings.