However, their Honours immediately went on to say:
"But although a trial judge may comment on the facts, the judge is not bound to do so except to the extent that the judge's other functions require it. Often, perhaps much more often than not, the safer course for a trial judge will be to make no comment on the facts beyond reminding the jury, in the course of identifying the issues before them, of the arguments of counsel."
76 In R v Machin (1996) 68 SASR 526 Olsson J distilled from the authorities a number of principles adherence to which ought to achieve a fair summing up. These include the need to explain, in a detached and dispassionate manner, the substance and legal implications of the defence; the need for the judge to appear to be neutral; the danger that the expression of personal views by a judge will overawe the jury, even in the face of conventional directions that the determination of the facts is entirely for the jury; and the need to take care in the mode of expression. His Honour then quoted from a Canadian decision in R v Pavlukoff (1953) 106 CCC 249 as follows:
"It seems an absurdity for a judge after telling the jury the facts are for them and not for him, then to volunteer his opinion of facts followed then or later by another caution to the jury that his own opinion cannot govern them and ought not to influence them. If his opinion ought not to govern or influence the jury then why give his opinion to the jury. To a person who is not a lawyer, but has some training in the science of correct thinking and some knowledge of the workings of the human mind, a judge who expresses his own opinions to the jury is in effect unconsciously perhaps but nevertheless subtly and positively undermining the plain instruction he has given the jury that 'the facts are for them and not for him'; in reality he is in true effect attempting to persuade the jury not to exercise their own minds freely (as in law he has told them they must do) but instead to be guided by the factual conclusions he volunteers to them."
77 His Honour went on the quote from a judgment of King CJ in R v O'Neil (1988) 48 SASR 51, and then to make the following observation of his own:
"I venture to suggest that such dictum was not intended to constitute a carte blanche for a trial judge to emphasise unduly the particular strengths of a prosecution case in a manner which is inconsistent with a fair, balanced and impartial analysis of the issues which a jury must consider. True it is that balance must, in one sense, constitute a reflection of the relative strengths of the Crown and defence cases, but it will rarely be appropriate for a trial judge to proffer what is tantamount to an expression of his or her personal assessment of the matter."
78 Senior counsel also made particular reference to authorities concerning the restraint that must be exercised by trial judges in putting to the jury responses to aspects of the defence case which are not drawn from the case expressly and explicitly put on behalf of the Crown. For example, in R v Heuston (1995) 81 A Crim R 387, Hunt CJ at CL said:
"Sometimes, of course, a judge is obliged - even in what might be described as the ordinary case - to draw the attention of the jury to an argument which has not been put by counsel, if it is necessary to do so in order to ensure that the jury has sufficient knowledge and understanding of the evidence to discharge their duty to determine the case according to the evidence. Some such occasions are obvious - where, for example, the principal 'defence' is one of alibi, yet there is clear evidence of intoxication which would be relevant to specific intention in the event that the alibi fails. Everyone realises that, from a tactical point of view, if counsel were to address upon such an issue of intoxication it would weaken the strength of his client's case on alibi, and trial judges should usually discuss the need to give directions as to such matters with counsel (in the absence of the jury) before the summing up commences. Other such occasions are not always so obvious, and - again, stated in very general terms in relation to the ordinary case - there will be no miscarriage of justice if arguments which may have been available on the evidence are not put by the judge in the summing up if they had not already been put by counsel. Sometimes, indeed, it may produce positive mischief if the judge raises arguments which could have been but which were not put or requested by counsel."
79 In R v RTB [2002] NSWCCA 104, this Court, constituted by Spigelman CJ, Wood CJ at CL and Kirby J, in a joint judgment, dealt with a case in which the trial judge had proposed for the benefit of the jury an explanation for an ambiguous piece of evidence given by a complainant in a sexual case, an explanation that had not been proffered by the Crown Prosecutor; the judge had also offered an explanation for the failure of the complainant to give a crucial piece of evidence, as a consequence of which a verdict of not guilty was directed. This explanation, also, had not been proffered by the Crown Prosecutor. The Court said:
"59 In each of the two respects of which complaint is now made, the intervention of the trial judge urged upon the jury a particular mode of thought. His Honour suggested that there could have been an explanation for the deficiency in the complainant's evidence, of a character which was not of itself based on any evidence but which, to a legal mind, would appear to be in each case a logical possibility. Juries are not required to think like that.