"In this context Ms Rozner for the second respondent, and Mr Shepherd for the third respondent, each contended that the hypersensitivity, on which the appellant relied, could only be established by medical evidence. They submitted that the evidence of the appellant was opinion evidence by way of “self-diagnosis”. I do not accept that submission. The evidence which has been foreshadowed to be given by the appellant was not opinion evidence. Rather, it seems that the appellant would seek to establish that when he was exposed to environmental tobacco smoke, he suffered from a combination of acute symptoms. No doubt he would seek to contrast those symptoms with the response of other persons to the same exposure. If his evidence stopped at that point, it would not contain any expression of opinion by the appellant. As I have stated, it is possible to conceive that, in some unusual cases, a tribunal of fact might accept that that evidence is sufficient to establish a relevant impairment. Of course whether a tribunal, in this case or in any case, accepted that evidence as establishing the impairment, would necessarily be a matter for determination on a full hearing of the complaint. However, for the purposes of a s.75(1) application at an interlocutory stage, such as in the present case, I do not consider that it would be correct to conclude that, if the appellant was confined to that evidence alone, without any expression of opinion, such evidence must necessarily fail to establish the impairment on which the appellant relies."