"The next matter of law about which I shall direct you is the question of lies told by the defendant and your approach to them. It is particularly with regard to the lies she admits she told to the police about thinking that Tom Cressman had only suffered minor injuries when she left the house. She told that lie both to the police and indeed to Dr. Turner. She told Dr. Turner, for example, that she saw some blood on herself and thought that she herself was hurt and that when she left the house she thought that Mr Cressman was after her. In addition, she told a number of lies in the days following her flight. In particular she sought to cast suspicion elsewhere by saying that he had been blackmailed. She admits that she told those lies. The reason she told those lies, say the defence, is that she was unable to bring herself to face the fact that she had, although in self-defence and accident killed the man she loved. …… The reason she told those lies say the defence is because she was unable to bring herself to face the fact that he had died in the circumstances she there described and after all it was the man she loved. When you are considering the question of any lies that you find the defendant told, you should not rely on any of them as supporting the prosecution’s case unless you are sure of the following: First, that the lie you are considering was a deliberate lie; secondly, it was not told for an innocent reason, for example, to bolster up a genuine defence as here, self-defence and accident. The reason is that people often do tell lies for innocent reasons. The fact that a person has told a lie is not indicative of guilt necessarily, because it might be a lie told, or lies told for an innocent reason or reasons. What you have to consider in this case is what the defendant herself said, that she did not think she would be believed. It is only if you are sure that the lie you are considering was told from a consciousness of guilt and a fear of the truth that you can use it as supporting the prosecution’s case. I emphasise that even then it can only support the prosecution’s case, but is not of itself and can never be of itself proof of guilt. There is one further matter on the question of lies. If you are considering the issue of provocation. Lies are not necessarily inconsistent with provocation. In this case the fact that she told lies about his being only slightly injured and the lie about the blackmail are not logically inconsistent with provocation and should not in your consideration be considered as being inconsistent with provocation. …"
"(The judge’s) approach appears to us to overlook the vital and incontestable fact that a man who has killed by reason of loss of self-control, and therefore faces arrest, trial and possible lengthy imprisonment, may have almost as strong reasons for attempting to conceal his deed and lie about his involvement as a man who has killed deliberately. … ..…The point is that the jury should be alerted to the fact that, before they can treat lies as tending towards the proof of guilt of the offence charged, they must be sure that there is not some possible explanation for the lies which destroys their potentially probative effect. Applying that concept to the present case, could the jury be sure that attempts to conceal the killing and lies were inconsistent with the appellant’s case that he had killed as a result of provocation, and pointed to murder. … In principle, however, the need for a warning along the lines indicated is the same in all cases where the jury are invited to regard, or there is a danger that they may regard lies told by the defendant, or evasive or discreditable conduct by him, as probative of his guilt of the offence in question. …"