R. v. Dexter, 2013 ONCA 744:
 The rule in Browne v. Dunn is not merely a procedural rule; it is a rule of trial fairness. The rule was summarized by this court in R. v. Henderson (1999), 44 O.R. (3d) 628 (C.A.), at p. 636 as follows:
This well-known rule stands for the proposition that if counsel is going to challenge the credibility of a witness by calling contradictory evidence, the witness must be given the chance to address the contradictory evidence in cross-examination while he or she is in the witness-box.
The cross-examiner gives notice by first putting questions to the witness in cross-examination that are sufficient to alert the witness that the cross-examiner intends to impeach his or her evidence, and second, by giving the witness an opportunity to explain why the contradictory evidence, or the inferences to be drawn from it, should not be accepted: see the comments of Lord Herschell in Browne v. Dunn, at pp. 70-71.
 The application of the rule prevents a witness from being "ambushed". However, it does not require the cross-examiner to "slog through a witness's evidence-in-chief putting him on notice of every detail the defence does not accept": see R. v. Verney (1993), 67 O.A.C. 279, at para. 28. Only the nature of the proposed contradictory evidence and its significant aspects need be put to the witness.
 The rule is also a rule of common sense. By enabling the trial judge to observe and assess the witness when he or she is confronted with contradictory evidence and given an opportunity to explain his or her position, the rule promotes the accuracy of the fact-finding process. In doing so, it enhances public confidence in the justice system.
 The effect that a court should give to a breach of the rule in Browne v. Dunnwill depend on a number of factors. In deciding how to address a breach, a trial judge may consider:
· The seriousness of the breach;
· The context in which the breach occurred;
· The stage in the proceedings when an objection to the breach was raised;
· The response by counsel, if any, to the objection;
· Any request by counsel to re-open its case so that the witness whose evidence has been impugned can offer an explanation;
· The availability of the witness to be recalled; and
· In the case of a jury trial, whether a correcting instruction and explanation of the rule is sufficient or whether trial fairness has been so impaired that a motion for a mistrial should be entertained.
Thus, the extent of the rule's application is within the discretion of the trial judge after taking into account the circumstances of the case: see R. v. Lyttle, 2004 SCC 5,  1 S.C.R. 193, at para. 65; R. v. Werkman, 2007 ABCA 130, 404 A.R. 378, at para. 9.
 There are at least two permissive options to rectify the breach. One is for the trial judge to take into account the failure to cross-examine when assessing a witness's credibility and deciding the weight to be given to that witness's evidence: see Werkman, at paras. 9-11; R. v. Paris (2000), 138 O.A.C. 287, at para. 22. Another is to allow counsel to recall the witness whose evidence has been impeached without notice. As Moldaver J.A. explained in R. v. McNeill (2000), 48 O.R. (3d) 212 (C.A.), at paras. 47-49, where the concern lies in the witness's inability to present his or her side of the story, if the witness is available and the trial judge is satisfied that recall is appropriate, the trial judge ought to offer the aggrieved party that opportunity. The mechanics of when and by whom the witness should be recalled should be left to the discretion of the trial judge. If the aggrieved party who is offered this option declines it, then the trier of fact would simply decide whether to believe all, part or none of the [later] witness's evidence regardless of whether the evidence was uncontradicted.
 Deference is owed to a trial judge's exercise of discretion in deciding how to deal with a breach of the rule unless error in principle is shown: see R. v. Blom(2002), 61 OR (3d) 51 (C.A.), at para. 20.