"Ordinarily, it is the province of the Crown to formulate and present the case for the prosecution which will, in due course, be summed up by the judge to the jury. There may, however, be other matters of fact or law which the trial judge, in the discharge of his duty to ensure a fair trial according to law, considers it necessary to put to the jury, even though not propounded or developed by the Crown. The fairness or unfairness of travelling beyond the ground covered by the Crown will, of course, be evaluated by the trial judge and will be to the forefront in his deciding how far, if at all, to put new considerations to the jury. It seems to me that, where a judge does cover fresh ground in terms that are correct in law and properly based on evidence in the case, at the highest his decision so to do will only be challengeable if it can be seen that the accused person was thereby placed at a tactical disadvantage. In such a situation, appellate intervention would be appropriate, not by reason of the judge having canvassed fresh ground simpliciter, but by reason of unfairness attending his so doing. The relevant unfairness will ordinarily be looked for in procedural considerations. The judge, drawing upon his own forensic experience, will be readily appreciative of the tactical considerations which will have governed counsel in the conduct of the case for the accused. Objections to evidence, lines of cross-examination and decisions upon the material to be advanced on behalf of the accused, not to mention the general trend of the final address to the jury made on behalf of the accused, will all, of course, have been governed by the nature of the Crown case as opened by the prosecutor and developed through evidence tendered on behalf of the Crown at the trial. It is readily understandable that, within these procedural and tactical fields, there could arise an element of real prejudice, if the judge, in his summing-up, raises new approaches available to, but not expressly relied upon, by the Crown. But in every case in which a question arises regarding the development of new approaches, the question concerning the judge at first instance, and on appeal the question concerning this Court, will be to determine whether in so doing there will be worked an unfairness to the accused."