On rare occasions a trial that has been completed and judgement rendered, may be re opened.
Moradkhan v. Mofidi, 2013 BCCA 132 deals with the BC Court of Appeal dealing with the legal issue of when it may be appropriate, or not, for a trial judge to ” re-open” a trial, after judgement has been delivered. Generally speaking, once that has occurred, the trial court is “functus”, and a remedy if available, is to appeal.
Following a three day summary trial the chambers judge delivered her reasons for judgment on April 15, 2011: 2011 BCSC 485. After release of that judgment, an application to reopen the trial was brought by the appellant wife, Ms. Moradkhan. The application did not complete in the allotted time, and the judge invited the parties to make written submissions. Both parties made additional submissions, including submissions on matters that were not part of the application to reopen. They both filed additional evidence. Based on these additional submissions and evidence, and without a further oral hearing, the judge delivered supplementary reasons for judgment on August 25, 2011, almost entirely replacing her earlier judgment: 2011 BCSC 1157. A final, clarifying judgment was released several months later on May 17, 2012: 2012 BCSC 722.
The appeal court found fault with Justice Loo’s use of her discretion, and ordered a new trial.
The legal principles that govern the exercise of a judge’s discretion to reopen a trial (before judgment has been entered, as was the case here) are well settled.
Appeal Court Rules
 In Mohajeriko v. Gandomi, 2010 BCSC 60, 80 R.F.L. (6th) 435, MacKenzie J. (as she then was), in a family division of property case strikingly similar on its facts to the case at bar, summarized the leading cases on this question, beginning at para. 20 of her reasons for judgment:
 The defendant relies on my discretion to re-open the trial under Rule 40(7):
40(7) Where a party omits or fails to prove some fact material to the party’s case, the court may proceed with the trial, subject to that fact being afterwards proved as the court shall direct …
 The application to reopen the trial is said to be based on the discovery of new evidence. That was the basis advanced for reopening in Clayton v. British American Securities Ltd.,  3 W.W.R. 257 (B.C.C.A.), which is generally regarded as the leading decision on the subject in this province.
 The Court of Appeal in Clayton held that the ability of a trial judge to reopen an issue before the order for judgment had been entered is an unfettered discretion, but one that is to be used sparingly. The basis for that principle is found in the judgment of Macdonald, J.A. at p. 295:
It is, I think, a salutary rule to leave unfettered discretion to the trial Judge. He would of course discourage unwarranted attempts to bring forward new evidence available at the trial to disturb the basis of a judgment delivered or to permit a litigant after discovering the effect of a judgment to re-establish a broken-down case with the aid of further proof. If the power is not exercised sparingly and with the greatest care, fraud and abuse of the Court’s processes would likely result.
 In Mandzuk v. Vieira (1983), 43 B.C.L.R. 347, McLachlin J. (as she then was), reviewed the principles upon which the court’s discretion under Rule 40(7) will be exercised (at page 350):
(a) The rule is to be “used sparingly, only if a clearly meritorious case is made out and where substantial injustice might otherwise be done, as no doubt it is a rule easily susceptible to abuse and liable, if too freely applied, to serve as an encouragement to carelessness”: [citation omitted].
(b) The rule is not designed to enable a party to put his case twice, but rather to prevent the claim being disposed of without consideration of its merits; [citation omitted].
(c) The rule should not be used to permit introduction of a substantial amount of new evidence relating generally to the issues in the case: Swami v. Lo (No. 2) (1979), 15 B.C.L.R. 321. It may be noted that the rule uses the word “fact” in the singular rather than referring to the more compendious term “evidence”.
(d) The rule refers to proof of “some fact” omitted, not to proof of opinions. It does not appear to permit reception after the trial of opinion evidence.
(e) The Court must be careful to avoid the abuse to which the rule is susceptible. In this connection, it is relevant to inquire into the reasons for the failure to prove the omitted fact at trial. While it is not essential to establish that the failure to tender the evidence at trial was the consequence of an accidental slip or oversight, such evidence counters the possibility that the applicant deliberately or heedlessly split his case thereby abusing the process of the Court.
 In Akkor v. Roulston, 2009 BCSC 1584, the defendant sought to re-open the trial to introduce new evidence about the sale of his properties. Wedge J. summarized the principles applicable to the reopening of an issue to receive new evidence at paras. 20 to 21 as follows:
 A trial judge’s ability to re-open an issue to hear new evidence before formal judgment has been entered is an unfettered discretion that is to be used sparingly: [citation omitted].
 The test for reception of new evidence following the completion of trial and the delivery of judgment is not controversial. The party seeking to adduce such evidence must satisfy the court on a balance of probabilities that (i) a miscarriage of justice would probably occur without the rehearing and (ii) that the evidence or argument he now wishes to present would probably change the result of the trial: [citation omitted].
 Wedge J. addressed the difficulty of achieving fairness as a moving target, quoting at para. 30 the following passage from Gilpin v. Gilpin (1990), 50 B.C.L.R. (2d) 251, 29 R.F.L. (3d) 250 (C.A.) at p. 7:
My second observation relates to the submission of counsel for the respondent that the value of the matrimonial home may well have fallen since the date of trial and that what may appear to be fairness to the wife is, in fact, unfairness to the husband, because of what may well be a decline in value. I am sympathetic to this submission but I consider that it is a result of the legislative scheme adopted in the Family Relations Act. Continuing fairness is impossible to achieve. Fairness at a particular point in time is the legislative goal.
 At para. 31 of Akkor, Wedge J. discussed the application of Gilpin in Hodgkinson v. Hodgkinson, 2004 BCSC 1630, aff’d 2006 BCCA 158, 53 B.C.L.R. (4th) 52:
In Hodgkinson, following the publication of the trial judgment, one of the parties applied to the trial judge to lead evidence that the proceeds from the sale of the matrimonial home were significantly less than anticipated in the judgment. At trial, the applicant had attempted to persuade the court to value the home at $2 million on the basis that when it was listed and sold it might sell for less than the listed price. The court instead valued the home at $2.2 million. The home was sold post-judgment for $2 million. The court refused the application to re-open the issue on the basis that the sale of the home – and the possibility that it would sell for less than the listing price – was contemplated in the reasons for judgment and was thus not “new evidence” that would have changed the result of the trial if it had been advanced earlier. Citing Gilpin, the court held that continuing fairness is difficult to achieve, and that fairness at a particular point in time is the goal. Fairness had been achieved at trial using a value of $2.2 million, and there was no injustice in maintaining the valuation at trial in all of the circumstances of the case.
 Finally, in Cheema v. Cheema, 2001 BCSC 298, 89 B.C.L.R. (3d) 179, the court noted that where a change in circumstances is, in effect, an argument that could have been presented at the original trial, the following principle from Sykes v. Sykes (1995), 6 B.C.L.R. (3d) 296 (C.A.), at para. 12 applies to bar the exercise of discretion to re-open: