"Where on a charge of murder there is evidence on which the jury can find that the person charged was provoked (whether by things done or by things said or by both together) to lose self-control, the question whether the provocation was enough to make a reasonable man do as he did shall be left to be determined by the jury; and in determining that question the jury shall take into account everything both done and said according to the effect which, in their opinion, it would have on a reasonable man."
"We do not take that view. We think that this was a matter which ought to have been left to the jury and that it cannot possibly be said that there was no evidence of the subjective test being applied because the evidence of the applicant himself was to be heard and considered in this context. Whether any jury would have believed him is an entirely different question, but when one asks oneself whether there was any evidence to support the plea of provocation, the answer is that there was evidence coming from the accused's mouth which he was entitled to have put before, and considered by, the jury. In a sense that is an end of the matter, except that there was some discussion in this Court as to the propriety of applying the proviso tosection 2(1) of the Criminal Appeal Act 1968 . [Counsel] submits in the alternative, with considerable force, that no reasonable jury could possibly have found that a reasonable man, subjected to the provocation to which this man had been subjected, would have acted as he did. Of course, if the jury had failed to hold that a reasonable man would have acted as the applicant did, then the defence of provocation would have gone. The jury did not have an opportunity of expressing a view on the matter. [Counsel] says that if one looks at the facts it is so obvious that no reasonable jury could have accepted the provocation plea that we ought to apply the proviso and maintain the finding of murder. We have thought a good deal about this because the point in a sense seems to be a new one. We are impressed by the fact that Parliament in the Act of 1957 has taken an unusual step of deliberately insisting that a particular issue shall be tried by the jury and no one else. In other words the reaction of the reasonable man must be assessed by the jury because the section says so. In this case no jury had an opportunity of expressing a view on the point at the Court of trial. There is no jury in this Court. If we apply the proviso we are in fact determining that issue otherwise than by the verdict of the jury. Although we are not prepared to go to the length of saying that the proviso is never appropriate in this kind of case, we do not feel that it would be right to apply it in this case."
"[Counsel] argues, and we agree, that although the section specifically requires that the question: 'Would a reasonable man have acted as the defendant did?' is to be left to the jury, this is generally true of other defences of which there is some evidence, for instance, a defence of alibi or a defence of self-defence. Take for example, the not uncommon situation, where the defendant says in evidence: 'I was not there' or 'I did not do it' but there is some evidence upon which an alternative defence of self-defence might be put forward. At trial before the jury it is extremely difficult, if not impossible, for counsel for the defendant to run those two defences in the alternative. But if there is some evidence upon which a defence of self-defence might be put, it is for the judge to draw the jury's attention to the appropriate evidence and to leave it for them to decide whether a defence is made out. Statute does not require that, common-law does. In our view, with all due respect to how the Court in Whitfield dealt with the matter, the section spells out the function of the judge and jury at trial, making them particularly clear, spelling them out as they would be in any case. The section is dealing with the trial not with the appeal. In deciding whether to apply the proviso, this Court has in a sense to put itself in the position the jury would have been in, to consider what a reasonable jury would or would not have done."
"We are clearly of the opinion, however, that as a matter of law this Court in an appropriate case may apply the proviso where there has been a misdirection by a failure of the judge to leave the issue of provocation to the jury."
"Having taken all the relevant evidence into account, we have concluded that a reasonable jury, if they had been properly directed to consider provocation, would have inevitably concluded that the reasonable man with those relevant characteristics of this appellant would not have been provoked to behave as the appellant did."
"Every man on trial for murder has the right to have the issue of manslaughter left to the jury if there is any evidence upon which such a verdict can be given. To deprive him of this right must of necessity constitute a grave miscarriage of justice and it is idle to speculate what verdict the jury would have reached."