Estoppel - Issue Estoppel and Criminal Law. R v Thompson
In R v Thompson (Ont CA, 2014), a criminal case, sets out with useful clarity some of the elements of the doctrine of issue estoppel, including some aspects that apply only to civil cases:
The Decision Requirement in Issue EstoppelThe case also discusses the residual discretion given to civil courts to waive application of the doctrine of issue estoppel in some cases:
 The doctrine of issue estoppel is concerned with particular issues common to two different pieces of litigation involving the same parties: R. v. Mahalingan, 2008 SCC 63 (CanLII), 2008 SCC 63,  3 S.C.R. 316, at para. 17. When applied to a trial, the doctrine focuses on particular determinations of the issues supporting the verdict, not on the ultimate verdict itself, which is the business of double jeopardy: Mahalingan, at para. 17.
 Where the doctrine of issue estoppel applies, it prevents the Crown from re-litigating an issue that has been decided in the accused’s favour with finality in a prior criminal proceeding: Mahalingan, at para. 31.
 The first requirement for a claim of issue estoppel is that an issue has been decided in a prior proceeding: Mahalingan, at paras. 49 and 52. The onus of proving this threshold requirement falls upon the accused who seeks to invoke the doctrine: Mahalingan, at para. 52.
 To satisfy this onus, an accused must show that the question was or must necessarily have been resolved on the merits in the accused’s favour in the earlier proceeding: Mahalingan, at para. 52. It is not enough to show that the evidence was adduced in an earlier proceeding and an acquittal entered: Mahalingan, at para. 52. It must be a necessary inference, either from the judge’s findings or from the fact of the result, that the issue was resolved in the accused’s favour: Mahalingan, at para. 52.
The Finality Requirement
 The second requirement of issue estoppel is that the estoppel-creating decision was final: Mahalingan, at para. 49. Findings on particular issues at trial are final, absent appellate reversal: Mahalingan, at para. 55.
 In many instances in which an accused seeks to invoke the preclusive effect of issue estoppel, the estoppel-creating proceeding and the proceeding in which the accused seeks to invoke the doctrine are both trials. It is clear from Mahalingan that the doctrine can operate in both jury and non-jury trials and where the finding said to create the estoppel was a positive finding or a finding based on reasonable doubt: Mahalingan, at para. 31.
 Since the proceeding alleged to create the estoppel in this case is not a trial proceeding, an issue arises whether a proceeding other than a trial can constitute an estoppel-creating proceeding that satisfies the finality requirement.
 In both Mahalingan and the earlier case of Grdic v. The Queen, 1985 CanLII 34 (SCC),  1 S.C.R. 810, both the estoppel-creating proceeding and that in which the doctrine was invoked were trials. But the terms “trial”, and “proceeding” and “proceedings”, appear in nearly equal measure in the decision in Mahalingan. On their face, the terms “proceeding” and “proceedings” include a trial but take in more ground than “trial”. The terms “proceeding” and “proceedings” could include both pre-trial and sentencing proceedings. Thus, it is helpful to examine some authorities in which an accused has tried to invoke issue estoppel when the estoppel-creating proceeding was not a criminal trial.
The Finality Requirement and Evidentiary Rulings
 The terms “proceeding” and “proceedings” would include a voir dire to determine the admissibility of evidence, as well as a preliminary inquiry at the conclusion of which a justice is required to decide whether there is sufficient evidence to put an accused on trial for the offence charged or any other indictable offence in respect of the same transaction.
 In Duhamel v. The Queen, 1984 CanLII 126 (SCC),  2 S.C.R. 555, the appellant was tried separately on two counts of robbery charged in the same indictment. At the first trial, a voir dire was conducted to determine the admissibility of certain statements made by the appellant. The trial judge ruled the statements inadmissible. Duhamel was acquitted. A different judge presided at the second trial. Despite objections based on issue estoppel, the second trial judge conducted a voir dire and admitted the statements ruled inadmissible at the first trial. Duhamel was convicted. On appeal, he argued that issue estoppel precluded the Crown from re-litigating the admissibility of the statements ruled inadmissible at the first trial.
 The Supreme Court of Canada unanimously affirmed the judgment of the Alberta Court of Appeal rejecting the extension of the doctrine of issue estoppel to include, as estoppel-creating findings, rulings on the admissibility of evidence, at least in the absence of a discrete right of appeal from decisions on admissibility.
 In Schweneke v. Ontario 2000 CanLII 5655 (ON CA), (2000), 47 O.R. (3d) 97 (C.A.), this court observed that issue estoppel would not apply where the accused had been discharged at the conclusion of a preliminary inquiry into charges of fraud, to preclude the determination in a subsequent civil action of whether he had in fact committed the alleged fraudulent acts. The court pointed out that a judge presiding at a preliminary inquiry does not make findings of fact. The judge decides only whether the evidence as a whole is sufficient to warrant a committal for trial. Such a determination could not found a subsequent claim of issue estoppel.
The Finality Requirement and Sentencing Proceedings
 In Punko, one of the appellants contended that issue estoppel could arise from findings of fact made by a sentencing judge under s. 724(2) of the Criminal Code after a jury trial. A majority of the Court concluded that such a finding could not serve as the basis for a claim of issue estoppel.
 Findings of fact under s. 724(2)(b) of the Criminal Code, the majority reasoned, do not constitute a judicial determination on the merits of the case. Rather, these findings are judicial determinations made only for the purpose of sentencing: Punko, at para. 11. Findings of fact made by the sentencing judge under s. 724(2)(b) of the Criminal Code cannot be relied upon to support a claim of issue estoppel: Punko, at para. 19.
 Revocation hearings under s. 724.6 are sentencing proceedings – more accurately perhaps, the continuation of sentencing proceedings: McIvor, at para. 12. Proof of a breach of a condition of the CSO is analogous to the proof of aggravating facts at the initial sentencing hearing: McIvor, at para. 12. The offender is not charged with an offence and is not at risk of conviction.
 To the extent that it remains unclear whether sentencing proceedings can serve as an estoppel-creating mechanism, it may be helpful to consider whether the policy considerations that are the genesis of the doctrine of issue estoppel favour one conclusion or the other in this case. The relevance of policy considerations has been recognized in non-criminal cases, albeit in the context whether a court has a discretion to refuse to apply issue estoppel if it will work an injustice, even where the preconditions to its application have been met: Penner v. Niagara (Regional Police Services Board), 2013 SCC 19 (CanLII), 2013 SCC 19, 356 D.L.R. (4th) 595, at para. 8; Danyluk v. Ainsworth Technologies Inc., 2001 SCC 44 (CanLII), 2001 SCC 44,  2 S.C.R. 460, at paras. 62 and 67.
 Issue estoppel serves three purposes. Each purpose is integral to a fair system of criminal justice:
i. fairness to the accused who should not be called upon to answer questions already decided in his or her favour;Mahalingan, at paras. 38-39, and 44-47. See also, Lucido v. Superior Court, 51 Cal. 3d 335 (1990), at p. 343, where the Supreme Court of California concluded that the failure to prove the commission of an offence at a probation revocation hearing did not preclude a subsequent prosecution for the same offence.
ii. the integrity and coherence of the criminal law; and
iii. the institutional values of judicial finality and integrity.
The Principles Applied
 I would give effect to this ground of appeal. In my view, a CSO revocation decision should not be classified as a final decision capable of giving rise to the operation of issue estoppel in a subsequent criminal trial. I have reached that conclusion for several reasons relating to:
i. the nature of revocation proceedings;
ii. the narrow scope of the doctrine of issue estoppel in criminal cases; and
iii. the purposes that underlie issue estoppel.
 For nearly half a century, the jurisprudence in this province has left no room for the exercise of a residual discretion in the application of the doctrine of issue estoppel. Where the requirements for the application of the doctrine have been established, issue estoppel applies to preclude re-litigation of an issue decided in the accused’s favour at a prior trial: R. v. Wright, 1965 CanLII 338 (ON CA),  2 O.R. 337 (C.A.), at pp. 340-341.
 In non-criminal proceedings, the Supreme Court of Canada has recognized a residual discretion in the application of issue estoppel. A court may decline to apply the doctrine where its application would create an injustice: Penner, at paras. 1, 31 and 36; Danyluk, at paras. 62-67. In the context of court proceedings, the residual discretion is to be accorded a very limited application: Danyluk, at para. 62; General Motors of Canada Ltd. v. Naken, 1983 CanLII 19 (SCC),  1 S.C.R. 72, at p. 101.
 The exercise of a residual discretion to decline to apply issue estoppel is governed by considerations of fairness. Unfairness may arise in two principal ways that overlap and are not mutually exclusive. First, the unfairness of applying issue estoppel may arise from the unfairness of the estoppel-creating proceeding. Second, even where the prior proceeding was conducted with scrupulous fairness and in accordance with its purposes, it may be unfair to use the results of the estoppel-creating proceeding to preclude the subsequent proceeding: Penner, at para. 39.
 To determine whether the operation of issue estoppel would create unfairness through according preclusive effect to the results of a prior proceeding in a subsequent proceeding requires a nuanced inquiry. Relevant factors in this inquiry may include, but are not limited to:
i. the nature and extent of any differences between the purposes, processes or stakes involved in the two proceedings (Penner, at paras. 42 and 45);
ii. the reasonable expectations of the parties in relation to the scope and effect of the prior proceeding as informed by the text and purpose of the enabling legislation (Penner, at para. 47);
iii. the risk of adding to the complexity and length of the estoppel-creating proceeding by attaching undue weight to its results through the application of issue estoppel (Penner, at para. 62);
iv. the availability of an appeal from the finding in the estoppel-creating proceeding (Danyluk, at para. 74); and
v. whether, in all the circumstances of the case, the application of issue estoppel would work an injustice (Danyluk, at para. 80).