“ 28. …..it is for an Appellant whose credibility is challenged as this Appellant’s credibility most emphatically was, and challenged in almost every possible respect, to put forward all the evidence he can and to deal with the discrepancies which arise. Even where the Secretary of State is not represented, the Appellant cannot assume that points which are not put by the Adjudicator to him for his comment are points which are to be regarded as accepted, especially if they are obvious points of contradiction or implausibility which he has failed to grapple with. It is not necessary for a fair hearing that every point of concern which an Adjudicator has, be put expressly to a party, where credibility is plainly at issue….”