R. v. P.J.B., 2012 ONCA 730 has a helpful review of the adequacy of jury instructions (and by implication reasons for judgment) and the duty to review evidence:
 Basic principles inform our decision about the adequacy of the trial judge's instructions in this case.
 Anyone charged with a criminal offence and tried by a jury is entitled to a properly, not perfectly, instructed jury: R. v. Jacquard,  1 S.C.R. 314, at para. 2.
 As described by this court in R. v. MacKinnon (1999), 132 C.C.C. (3d) 545 (Ont. C.A.), at para. 27, a trial judge's final instructions must leave the jury with a clear understanding of:
• the factual issues to be resolved;
• the legal principles governing the factual issues and the evidence adduced at trial;
• the positions of the parties; and
• the evidence relevant to the positions of the parties on the issues.
 In their final instructions most trial judges include a discrete statement of the positions of the parties, often a repetition of a brief summary prepared by counsel at the judge's request. What controls, however, is substance not form. In the end, however the message is delivered, jurors must be left with a clear understanding of each counsel's position. To the extent that the positions may vary among counts in a multiple count indictment, the position on each should be made clear.
 The responsibility of the trial judge to relate the evidence to the issues raised by the defence involves two components. The first is a review of the evidence. The second is a relation of the evidence to the position of the defence. Except in rare cases, where it would be unnecessary to do so, a trial judge must review the substantial parts of the evidence and give the jury the position of the defence so that the jury appreciates the value and effect of that evidence: Azoulay v. The Queen,  2 S.C.R. 495, at pp. 497-498. Typically, trial judges review the evidence in the context of the various issues and indicate what parts of the evidence support the positions of the respective parties on those issues: MacKinnon, at para. 29. Judicial review of the evidence refreshes the jurors' memory of the evidence given. Judicial relation of the evidence to the issues improves jurors' understanding of the particular aspects of the evidence that bear on their decision on each essential issue in the case.
 A trial judge is under no obligation to review all the evidence adduced at trial: MacKinnon, at paras. 29-30; and R. v. Daley, 2007 SCC 53,  3 S.C.R. 523, at paras. 55-56. Nor is a trial judge required to review the same evidence more than once where the evidence relates to more than one issue, provided the judge makes it clear to the jury that the evidence is relevant for more than one purpose: Jacquard, at paras. 14 and 16.
 Trial judges have considerable latitude in connection with the volume of evidence they review and relate to the various issues the jury will be called upon to decide: R. v. Royz, 2009 SCC 13,  1 S.C.R. 423, at para. 3; and Daley, at para. 57. It follows that the decisions of trial judges about the volume of evidence they choose to review in final instructions are owed substantial deference by appellate courts. The failure of a trial judge to mention individual items of evidence will not be fatal unless the items omitted constitute the sole evidentiary foundation of a defence: R. v. Demeter (1975), 25 C.C.C. (2d) 417 (Ont. C.A.), at p. 436, affirmed on other grounds  1 S.C.R. 538.
 The obligation to review the substantial parts of the evidence and to relate it to the issues raised by the parties is that of the trial judge, not counsel, whether prosecuting or defending. The closing addresses of counsel cannot relieve the trial judge of the obligation to ensure that the jury understands the significance of the evidence to the issues in the case, although the judge can consider the closing addresses of counsel in deciding how to discharge his or her obligations: MacKinnon, at para. 32; Royz, at para. 3; and R. v. Garon, 2009 ONCA 4, 240 C.C.C. (3d) 516, at para. 84.
 Appellate review of the adequacy of jury instructions requires a functional approach in which we test the instructions against their ability to fulfill the purposes for which final instructions are given: Jacquard, at paras. 32 and 41; and MacKinnon, at para. 27.
 Jury charges do not take place in isolation, but in the context of the trial as a whole. Appellate review of the adequacy of jury charges must acknowledge this reality, especially where the complaint is about the extent to which the trial judge has reviewed the evidence in final instructions. Appellate review on this issue includes consideration of the complexity and volume of the evidence adduced at trial, the extent of its review by counsel in their closing addresses, the length of trial proceedings, the issues to be resolved by the jury, the effect of a more complete and balanced review of the evidence, and whether counsel objected to the charge on the ground advanced on appeal. The test is one of fairness: Daley, at para. 57. Provided the evidence is left to the jury in a way that will permit the jurors to fully appreciate the issues raised and the defences advanced, the charge will be adequate: Daley, at para. 57.
 A consequence of the functional approach to jury instructions and their review by appellate courts is the absence of any requirement that the instructions conform with or follow a specific structure. Substance prevails, not form. That said, it is hard to controvert the principle that organized instructions are more likely to inform the understanding of the jury than are unorganized or disorganized directives. Final instructions that display an overall organization, as well as an organized approach to individual parts, seem inherently more likely to fulfill the purposes for which instructions are given.
 Among other things, unorganized or disorganized final instructions may result in:
• the omission of essential instructions;
• the inclusion of irrelevant or superfluous instructions; and
• the unnecessary repetition of instructions already given.
In the result, the instructions may become needlessly complex, lengthy and confusing to the jury, and distract jury members from an informed decision on the essential and controverted issues in the case: R. v. Rowe, 2011 ONCA 753, 281 C.C.C. (3d) 42, at para. 52.
 In some cases, the unnecessary complexity of a jury charge may divert the jury's attention from the critical issues in the case to such an extent that a new trial may be required: Rowe, at para. 52; and R. v. Hebert,  2 S.C.R. 272, at para. 13.
 Multiple count indictments, especially those in which the determination on each count depends on evidence limited to that count and which may involve bases of liability or defences different than those in play on other counts, impose a greater burden on trial judges in their final instructions. Each count is separate. Each requires a separate verdict. Each will often require legal instructions that differ from those that apply to other counts. Common features can be incorporated by judicial shorthand in final instructions, but where different principles are at work, they must be clearly stated to ensure they are appreciated by the jury.