The appellant Police Chief Inspector, when her right to carry out counselling in staff appraisals was ended after there were complaints made against her, had been subjected to a detriment. However, she had failed to prove that it was on the grounds of her sex because she could not show that, as a comparator, a male Chief Inspector in the same position would have been treated differently.Appeal from the Court of Appeal in Northern Ireland allowing an appeal by way of case stated from the decision of an industrial tribunal that the appellant ('S') had been discriminated against on the grounds of her sex. S was a Chief Inspector in the traffic branch of the respondent Royal Ulster Constabulary ('RUC'). In that rank it was the practice for her to carry out counselling in respect of all staff appraisals of constables in the urban traffic division. Following a complaint made about her conduct of appraisals, S was removed from appraisal duties. She lodged an application with the industrial tribunal ('the tribunal') complaining that she had been unlawfully discriminated against on the grounds of her sex under Arts.3(1) and 7 of Part II, and Art.8(2) of Part III, of the Sex Discrimination (Northern Ireland) Order 1976. The tribunal unanimously concluded that S had been less favourably treated when her right to continue to do appraisals had been removed and that this less favourable treatment had been on the grounds of her sex. The RUC stated a case to the Court of Appeal on the following questions of law: (i) whether the tribunal had been correct in holding that the male comparators chosen were not "materially different" within the meaning of Art.7 of Part II of the 1976 Order; (ii) whether the tribunal had been correct in holding that the RUC had treated S less favourably than they treated or would treat other persons; (iii) whether the tribunal had been correct in its application of the burden of proof; and (iv) whether the tribunal had been entitled on the facts to hold that S had been treated less favourably on the grounds of her sex. The Court of Appeal held that: (a) S had not suffered detriment; (b) there had been circumstances in S's case that did not apply to the other chief inspectors, in that complaints had been made about her performance, and for that reason the other Chief Inspectors were not valid comparators; and (c) although S had been subjected to different treatment there had been insufficient evidence to furnish a basis for a finding that this was on the grounds of her sex. S appealed.HELD: (1) S had been subjected to a detriment within the meaning of Art.8(2)(b) of the Order (see Chief Constable of West Yorkshire Police & Ors v Mr R Kahn (2001) 1 WLR 1947). (2) The determination of less favourable treatment required a comparison to be made between S's case and the case of an actual or hypothetical male officer in the RUC. Article 7 required that in making a comparison for the purposes of Art.3(1)(a) between the case of the female complaint and the case of a male comparator, actual or hypothetical, the relevant circumstances in the one case had to be the same or not materially different in the other. The complaints made about S were relevant circumstances in her case and it was not compliant with Art.7 to compare her case with that of a male Chief Inspector against whom no complaints had been made. S had failed to show that at least one other Chief Inspector who had been in the same position as she was had been treated differently. (3) S did not rely on a hypothetical male comparator ie a male Chief Inspector, in respect of whom similar complaints in relation to appraisal reports or the discharge of somewhat similar duties had been made, but based her case on a comparison with actual male Chief Inspectors against whom no complaints had been made. There had been no evidence before the tribunal that would have entitled them to find that if similar complaints had been made against a male Chief Inspector he would have been treated more favourably than S. (4) The tribunal had failed to give adequate reasons for their decision that the treatment that S had received was on the grounds of her sex.Appeal dismissed.
 UKHL 11