Abuse of Process - Contrasted with Issue Estoppel and Res Judicata. Canadian Imperial Bank of Commerce v. Canada
In Canadian Imperial Bank of Commerce v. Canada (Fed CA, 2023) the Federal Court of Appeal considered (and necessarily endorsed by their dismissal of the appeal) a Tax Court's contrast between the doctrines of issue estoppel and abuse of process:
 The Tax Court Judge cited the three requirements for issue estoppel as set out by the Supreme Court of Canada in Angle v. Minister of National Revenue, 1974 CanLII 168 (SCC),  2 S.C.R. 248:. Duhamel v. Canada (Attorney General)
 ... (1) that the same question has been decided; (2) that the judicial decision which is said to create the estoppel was final; and, (3) that the parties to the judicial decision or their privies were the same persons as the parties to the proceedings in which the estoppel is raised or their privies ... The Tax Court Judge noted, in paragraph 28 of his reasons, that once the three requirements are satisfied, the Court retains the discretion to not apply issue estoppel:
Essentially, the court's exercise of discretion either to apply or not to apply issue estoppel with respect to a given case, once all three formal requirements are satisfied, must be guided by the underlying policy concerns of res judicata and good sense. The Tax Court Judge noted that cause of action estoppel, issue estoppel and abuse of process are all concerned with similar policy principles. Abuse of process is more flexible as it does not have the same specific requirements as cause of action estoppel or issue estoppel.
 For the doctrine of abuse of process, the Tax Court Judge cited, at paragraph 30 of his reasons, the following summary of the decision of the Supreme Court in Toronto (City) v. Canadian Union of Public Employees, Local 79, 2003 SCC 63,  3 S.C.R. 77 in Donald J. Lange, The Doctrine of Res Judicata in Canada, 5th ed (Markham: LexisNexis Canada Inc., 2021), c. 1 at §4 (Lexis e-book):
 Lange summarizes the Supreme Court of Canada's analysis in Toronto (City) regarding the abuse of process doctrine as follows: The Tax Court Judge also noted:
1. The doctrine is not encumbered by the specific requirements of res judicata.
2. The proper focus for the application of the doctrine is the integrity of the judicial decision-making process.
3. Relitigation may be necessary to enhance the credibility and effectiveness of judicial decision-making when, for example, there are special circumstances.
4. The interests of the parties, who may be twice vexed by relitigation, are not a decisive factor.
5. The motive of a party in relitigating a previous court decision for a purpose other than undermining the validity of the decision is of little import in the application of the doctrine.
6. The status of a party, as a plaintiff of defendant, in the relitigation proceeding is not a relevant factor.
7. The discretionary factors that are considered in the operation of the doctrine of issue estoppel are equally applicable to the doctrine of abuse of process by relitigation.
 Citing Justice McLachlin (as she then was) in R v Scott, [1990 CanLII 27 (SCC),  3 S.C.R. 979] the Supreme Court of Canada states in Toronto (City) that “abuse of process may be established where: (1) the proceedings are oppressive or vexatious; and, (2) violate the fundamental principles of justice underlying the community's sense of fair play and decency.”
In Duhamel v. Canada (Attorney General) (Fed CA, 2022) the Federal Court of Appeal cited several means available to courts to prevent abuses of their process:
 In Danyluk v. Ainsworth Technologies Inc., 2001 SCC 44, the Supreme Court of Canada outlined a number of techniques developed to prevent an abuse of the decision-making process:. Boily v. Canada
" The law has developed a number of techniques to prevent abuse of the decision-making process. One of the oldest is the doctrine estoppel per rem judicatem with its roots in Roman law, the idea that a dispute once judged with finality is not subject to relitigation: Farwell v. The Queen ""(1894), "1894 CanLII 72 (SCC), "22 S.C.R. 553"", at p. 558""; Angle v. Minister of National Revenue, "1974 CanLII 168 (SCC), " 2 S.C.R. 248"", at pp. 267-68"". The bar extends both to the cause of action thus adjudicated (variously referred to as claim or cause of action or action estoppel), as well as precluding relitigation of the constituent issues or material facts necessarily embraced therein (usually called issue estoppel): G. S. Holmested and G. D. Watson, Ontario Civil Procedure (loose-leaf), vol. 3 Supp., at 21 s. 17 et seq. Another aspect of the judicial policy favouring finality is the rule against collateral attack, i.e., that a judicial order pronounced by a court of competent jurisdiction should not be brought into question in subsequent proceedings except those provided by law for the express purpose of attacking it: Wilson v. The Queen, "1983 CanLII 35 (SCC), " 2 S.C.R. 594""; R. v. Litchfield, "1993 CanLII 44 (SCC), " 4 S.C.R. 333""; R. v. Sarson, "1996 CanLII 200 (SCC), " 2 S.C.R. 223"".
In Boily v. Canada (Fed CA, 2021) the Federal Court of Appeal considers abuse of process compared with res judicata and collateral attack. The context was the striking of a second expert report by the Prothonotary after the striking of a similar first expert report, in an obvious re-attempt to have the contents accepted as evidence [also para 41-80]:
 This appeal does not involve any new law or the protection of some fundamental right despite Mr. Boily’s able arguments to convince us to the contrary. It only calls for the application of the well-established doctrines established in Toronto (City) v. C.U.P.E., Local 79, 2003 SCC 63,  3 S.C.R. 77 (CUPE) – particularly abuse of process — to the somewhat unusual and specific circumstances of this matter. . Curtis v. Pinto
 As noted in CUPE, the doctrines of res judicata, issue estoppel, collateral attack and abuse of process are complementary and interrelated, and more than one doctrine may support a particular outcome (in this case, striking out). I therefore do not need to address them individually as one is sufficient to determine this appeal.
 In the present matter, Mr. Boily made a strategic decision not to appeal the Gagné Judgment and to unilaterally file the Second Rosenblum Report without seeking any intervention of the case manager or another member of the Federal Court.
 Such situation does not fit the usual fact pattern for the application of res judicata, as it is Mr. Boily’s conduct, not a statement of claim or motion brought by him, which is in question. Res judicata typically involves looking at two distinct proceedings. Both the Federal Court and Prothonotary Tabib found that Mr. Boily was trying to do indirectly what Gagné J. had refused to do in his appeal before her. On such facts, I believe that it is appropriate to determine this appeal based on the complementary doctrine of abuse of process relied upon by Prothonotary Tabib.
 It is clear from CUPE that the doctrine of abuse of process is wider than the doctrines of res judicata and collateral attack, for it is not restricted to the same technical requirements. In all of its applications, the primary focus of the doctrine of abuse of process is the integrity of the Court’s process and the adjudicative functions of the courts, thus the focus is less on the interest of the parties, and the motive of a party like Mr. Boily cannot be determinative (CUPE at paras. 42, 43 and 45).
In Curtis v. Pinto (Ont CA, 2019) the Court of Appeal commented as follows on abuse of process:
 As the motion judge noted, citing Toronto (City) v. C.U.P.E., Local 79, 2003 SCC 63 (CanLII),  3 S.C.R. 77, at para. 51,. Wright v Urbanek
the doctrine of abuse of process concentrates on the integrity of the adjudicative process … if the result in the subsequent proceeding is different from the conclusion reached in the first one on the very same issue, the inconsistency, in of itself, will undermine the credibility of the entire judicial process, thereby diminishing its authority, its credibility and its aim of finality.As this court stated in Canam Enterprises Inc. v. Coles (2000), 2000 CanLII 8514 (ON CA), 51 O.R. (3d) 481, at para. 31, and as the motion judge further noted, the doctrine of abuse of process “can be relied upon by persons who were not parties to the previous litigation”.
In Wright v Urbanek (Ont CA, 2019) the Court of Appeal comments broadly on the similarity between abuse of process and isue estoppel:
 The doctrine of abuse of process arises out of the court’s inherent jurisdiction to prevent misuse of the court’s procedure in a way that would bring the administration of justice into disrepute. It is a flexible doctrine unencumbered by the specific requirements of concepts such as issue estoppel: Toronto (City) v. C.U.P.E., Local 79, 2003 SCC 63 (CanLII),  3 S.C.R. 77, at para. 35. One circumstance in which abuse of process has been applied is to strike out an action where the litigation before the court is in essence an attempt to relitigate a matter the court has already decided: see Behn v. Moulton Contracting Ltd., 2013 SCC 26 (CanLII),  2 S.C.R. 227, at paras. 39-41; Toronto (City) v. C.U.P.E., Local 79, at paras. 35-38.. The Catalyst Capital Group Inc. v. VimpelCom Ltd.
In The Catalyst Capital Group Inc. v. VimpelCom Ltd. (Ont CA, 2019) the Court of Appeal states this on the doctrine of abuse of process:
 It is well-recognized that the re-litigation of issues that have been before the courts in a previous proceeding will create an abuse of process. As stated by the Supreme Court of Canada in Toronto (City) v. C.U.P.E., Local 79, 2003 SCC 63 (CanLII),  3 S.C.R. 77, at para. 52:. Winter v Sherman Estate
[F]rom the system’s point of view, relitigation carries serious detrimental effects and should be avoided unless the circumstances dictate that relitigation is in fact necessary to enhance the credibility and the effectiveness of the adjudicative process as a whole. The abuse of process doctrine applies to prevent the attempt to impeach a judicial finding by re-litigation in a different forum: C.U.P.E., at para. 46. It is a flexible doctrine unencumbered by the mutuality of parties requirement that applies to issue estoppel and cause of action estoppel: C.U.P.E., at para. 37. While abuse of process does include a finality requirement, that requirement is met in this case because the Supreme Court dismissed Catalyst’s application for leave to appeal from this court’s decision in the Moyse Action.
 The need to protect the integrity of the adjudicative functions of courts compels a bar against re-litigation: C.U.P.E., at para. 43. If re-litigation leads to the same result, there will be a waste of judicial resources, and if it leads to a different result, the inconsistency will undermine the credibility of the judicial process: C.U.P.E., at para. 51. The law thus seeks to avoid re-litigation primarily for two reasons: first, to prevent overlap and wasting judicial resources; and second, to avoid the risk of inconsistent findings: Petrelli v. Lindell Beach Holiday Resort Ltd., 2011 BCCA 367 (CanLII), 24 B.C.L.R. (5th) 4, at para. 71; see also C.U.P.E., at para. 51; Donald J. Lange, The Doctrine of Res Judicata in Canada, 4th ed. (Markham, ON: LexisNexis Canada Inc., 2015), pp. 217-218.
 Catalyst’s submission that abuse of process is not intended to prevent the raising of a separate cause of action in a subsequent action should be rejected. As previously discussed, Catalyst could have raised the claims it advances in the Current Action in the Moyse Action. It elected not to. As this court recently held, abuse of process applies where issues “could have been determined” but were not: Winter v. Sherman Estate, 2018 ONCA 703 (CanLII), 42 E.T.R. (4th) 181, at para. 7. Moreover, it also applies to prevent re-litigation of previously decided facts: Winter, at para. 8. As previously stated, for Catalyst to succeed in the Current Action, a court would have to reach different factual findings from those of Newbould J. on the reasons why Catalyst failed to acquire Wind.
 Moreover, none of the factors the Supreme Court outlined in C.U.P.E. that would permit re-litigation apply in this case. The Supreme Court stated, at para. 52, that it might be appropriate to permit re-litigation in the following circumstances:
1) When the first proceeding is tainted by fraud or dishonesty;
2) When fresh, new evidence, previously unavailable, conclusively impeaches the original results; or
3) When fairness dictates that the original result should not be binding in the new context.
In Winter v. Sherman Estate (Ont CA, 2018) the Court of Appeal points out the similarity between abuse of process and issue estoppel, and how abuse of process may be applied where elements of issue estoppel are lacking:
 Further, the appellants too narrowly construe the doctrine of abuse of process. This doctrine is flexible and unencumbered by the specific requirements of res judicata or issue estoppel: Behn v. Moulton Contracting Ltd., 2013 SCC 26 (CanLII),  2 S.C.R. 227, at para 40; Toronto (City) v. C.U.P.E., Local 79, 2003 SCC 63 (CanLII),  3 S.C.R. 77, at para. 42. Where a precondition for issue estoppel has not been met, such as mutuality of parties, courts have turned to the doctrine of abuse of process to preclude re-litigation of the same issue: C.U.P.E., at para. 37. While the doctrine is similar to issue estoppel in that it can bar litigation of legal and factual issues “that are necessarily bound up with the determination of” an issue in the prior proceeding, abuse of process also applies where issues “could have been determined”: Danyluk v. Ainsworth Technologies Inc., 2001 SCC 44 (CanLII),  2 S.C.R. 460, at para. 54; Aba-Alkhail v. University of Ottawa, 2013 ONCA 633 (CanLII), 363 D.L.R. (4th) 470, at para. 13; McQuillan v. Native Inter-Tribal Housing Co-Operative Inc. (1998), 1998 CanLII 6408 (ON CA), 42 O.R. (3d) 46 (C.A.), at paras. 8, 10. As such, the doctrine of abuse of process is broader than res judicata and issue estoppel and applies to bar litigation that, if it proceeded, would “violate such principles as judicial economy, consistency, finality and the integrity of the administration of justice”: C.U.P.E., at para. 37.. Skypower CL 1 LP v Ontario Power Authority
 We agree with the motion judge that the whole evidentiary underpinning of this action is the same as that of the Royal Trust action and that it would be unfair and an abuse of process to allow the appellants to “in effect, re-litigate their case, with a new theory, to see if this one will succeed where previous theories have failed”. Moreover, the doctrine of abuse of process applies to prevent re-litigation of previously decided facts: Intact Insurance Company v. Federated Insurance Company of Canada, 2017 ONCA 73 (CanLII), 134 O.R. (3d) 241, at para. 28, leave to appeal refused,  S.C.C.A. No. 98; R. v. Mahalingan, 2008 SCC 63 (CanLII),  3 S.C.R. 316, at para. 46; C.U.P.E., at para 37. As the motion judge determined, the relief and issues put forward by the appellants in these proceedings “arise from the same relationships and subject matter that have already been dealt with by Perell J. and the Court of Appeal” in the Royal Trust action.
In Skypower CL 1 LP v. Ontario Power Authority (Ont CA, 2015) the same theme was canvassed, that abuse of process can apply to prohibit the raising in future of issues which could have been raised in past proceedings:
 As the motion judge found, the appellants could have raised in the judicial review application—in which they attacked the lawfulness of the Minister’s direction to the OPA, and the resulting changes to the FIT program — the allegation that they were specifically targeted. As this court said in Aba-Alkail v University of Ottawa, 2013 ONCA 633 (CanLII) at para. 12:. Phillion v. Ontario (Attorney General)
…the abuse of process doctrine can apply not only to bar re-litigation of issues that were actually determined in the administrative process, but also to issues that could have been determined (Ontario v. Lipsitz, 2011 ONCA 466 (CanLII) at para. 88). This gives further incentive to raise all issues at the administrative proceeding and to participate "with full vigour". The motion judge was correct in deciding that the appellants’ failure to raise the targeting allegation in the judicial review proceedings was sufficient for the abuse of process doctrine to apply.
 The issue then, is whether the motion judge erred in deciding not to exercise her discretion to permit the action to proceed nevertheless. She found the appellants had a good opportunity to put their position forward in the judicial review proceedings, and the respondents’ refusal to produce certain documents in those proceedings did not result in any unfairness. Her conclusion that “not applying the doctrine of abuse of process in this case would offend the principle of finality and undermine the credibility of the judicial process” is deserving of deference.
 We need not deal with the appellants’ other arguments, as the finding of abuse of process forecloses their equitable as well as their legal claims.
In Phillion v. Ontario (Attorney General) (Ont CA, 2014) the Court of Appeal the court repeats the same theme about the relationship of abuse of process with issue estoppel:
 As it relates to this case, the doctrine has been applied to prevent relitigation when the requirements of issue estoppel cannot be met (as is the case here, because the parties to the two proceedings are not the same), but when “allowing the litigation to proceed would nonetheless violate such principles as judicial economy, consistency, finality and the integrity of the administration of justice”: C.U.P.E., at para. 37. The court emphasized that the focus of the doctrine of abuse of process is less on the parties and more on “the integrity of judicial decision making as a branch of the administration of justice”: C.U.P.E., at para. 43.But at the same time cites this passage from the Supreme Court of Canada:
 In R. v. Mahalingan, 2008 SCC 63 (CanLII), 2008 SCC 63,  3 S.C.R. 316, at para. 42, McLachlin C.J. expressed the view that the doctrine of abuse of process is vague and variable, pointing out that the Supreme Court has said that “successful reliance on the doctrine will be extremely rare”. Importantly for this appeal, she stated further, at para 42, that:
To date, the doctrine has not been much used to protect against relitigation, and indeed there is authority for the proposition that relitigation, without more, simply does not reach the threshold required for a finding of abuse of process. [Citation omitted.]