1. On 12 September 2009, the Appellant killed his cohabitee. The Appellant admitted to the killing and pleaded guilty to manslaughter. The key disagreement between the Respondent (the “Prosecution”) and the Appellant was whether the defence of provocation or diminished responsibility was available to the Appellant, which would reduce the charge of murder to manslaughter. 2. For the same killing, the Appellant was tried for and convicted of murder three times. The Appellant appealed the latest conviction on the basis that the trial judge misdirected the jury by failing to draw their attention to the relevance of the psychiatric evidence adduced in support of diminished responsibility to whether the Appellant had lost his self-control because of provocation. The Court of Appeal (the “CA”) unanimously allowed the appeal and quashed the conviction. 3. The majority of the CA ordered a third re-trial for murder (i.e. a fourth trial). They did so after considering numerous factors. These included the seriousness of murder, the strength of the case against the Appellant, how the Appellant’s counsel gained tactical advantage by failing to point out the relevance of the psychiatric evidence to the Appellant’s loss of self-control and this was the first trial where the Appellant raised the defence of diminished responsibility. 4. The issue before this Court was whether, by ordering a third retrial for murder, the exercise of discretion by the majority of the CA miscarried. 5. This Court held that first, the Appellant’s counsel had not deliberately chosen to keep quiet about the relevance of psychiatric evidence to the question of loss of self-control and let the trial judge err for some tactical advantage. No tactical advantage would be gained by the Appellant’s counsel in doing so. In fact, neither the Prosecution nor the trial judge realised the relevance either and all three were on the same footing. Even if the Appellant’s counsel were at fault, it would be highly debatable that fault should be attributed to the Appellant. Secondly, the fact that diminished responsibility was raised for the first time at the third trial was not something that should count against the Appellant. There was evidence supporting the defence and the Appellant was entitled to run it. Whether raising it earlier could have prevented problems was highly speculative. Regardless, given the highly technical nature of this defence, any fault for not raising it earlier should not lie with the Appellant. By considering these two factors, the majority had taken into account irrelevant considerations when ordering the third re-trial. The CA’s exercise of discretion miscarried. 6. This Court held that the discretion should be re-exercised and in doing so decided not to order a third retrial. There were five matters which were particularly important to reaching this decision: 6.1. First, if a third retrial was ordered, this would be a fourth trial for murder, which would be oppressive to the Appellant on the facts of the present case. 6.2. Second, the Appellant had already been remanded in custody for a period of time equivalent to a sentence of imprisonment of almost 27 years (after taking into account the discount for an early guilty plea and remission for good behaviour). It went well beyond the higher end of the usual range of sentences for manslaughter. 6.3. Third, given the long lapse of time, the Appellant’s and other witnesses’ memory of the relevant events must be affected, affecting the quality of the evidence and demeanour of the witnesses. Since the Appellant’s performance in the witness box would be important to the issues in the fourth trial, the Court was not of the view that it could be satisfactorily remedied by the trial judge giving appropriate directions to the jury. 6.4. Fourth, as for the strength of the Prosecution case for murder, the Appellant’s case on provocation was at least reasonably arguable and a murder verdict was certainly not a foregone conclusion. 6.5. Fifth, even though the quashing of the convictions in the first and third trials was partly due to mistakes made by the Appellant’s counsel, this carried little weight. In the first trial, the primary responsibility for the mistake lay with the Prosecution. For the third trial, the mistake made did not arise out of a deliberate, tactical decision by the Appellant’s counsel. Disposition 7. Accordingly, the appeal was unanimously allowed. 8. This Court quashed the order for a third retrial, entered a conviction for manslaughter on the basis of provocation and sentenced the Appellant to such sentence that would allow for his immediate release from custody.