In Madarassy v Nomura International plc the Court of Appeal has issued a lengthy and discursive judgment on the burden of proof in discrimination cases. It held (among other things) that a claimant must show more than a difference in sex and a difference in treatment to establish a prima facie case of sex discrimination. The ruling has reinforced the point in Igen v Wong that a claimant must show more than the mere possibility of discrimination before the burden of proof shifts to the respondent: the primary facts must be such that a reasonable tribunal, having heard all the evidence from both sides, could conclude that the respondent committed (not merely "could have committed") the discriminatory act.