"The statute calls for a simple comparison between the treatment given to Mr Khan and the treatment which would have been given to a police officer who had not done a protected act. Protected act aside, the hypothetical comparator should be in the same position as Mr Khan, not in an admittedly different but allegedly comparable position."
" Contrary to views sometimes stated, the third ingredient ('by reason that') does not raise a question of causation as that expression is usually understood. Causation is a slippery word, but normally it is used to describe a legal exercise. From the many events leading up to the crucial happening, the court selects one or more of them which the law regards as causative of the happening. Sometimes the court may look for the 'operative' cause, or the 'effective' cause. Sometimes it may apply a 'but for' approach. For the reasons I sought to explain in Nagarajan v London Regional Transport[2001] 1 AC 502 , 510-512, a causation exercise of this type is not required either by section 1(1)(a) or section 2. The phrases 'on racial grounds' and 'by reason that' denote a different exercise: why did the alleged discriminator act as he did? What, consciously or unconsciously, was his reason? Unlike causation, this is a subjective test. Causation is a legal conclusion. The reason why a person acted as he did is a question of fact."