Ontario: Court of Appeal on the knowledge required to plausibly infer liability

The Court of Appeal decision in Di Filippo v. Bank of Nova Scotia explains the degree of knowledge required to know the s. 5(1)(a) discovery matters. This includes a clarification that the knowledge necessary to plausibly infer liability is not actual knowledge of the discovery matters. Actual knowledge requires knowledge of the material facts upon which to plausibly infer liability.

Perhaps like me you’ll find this distinction somewhat obtuse. What’s the difference between plausibly inferring liability per se and plausibly inferring liability based on material facts? Practically speaking, I think the point the court is making is that if you plausibly infer liability per se you have a suspicion of liability, but if you make that inference based on material facts, you have more than a suspicion. And so it’s just a different way of formulating the “more than a suspicion, less than certainty” standard that the court applied prior to Grant Thornton.

Here are the relevant paragraphs:

[54]      The court explained how to assess the plaintiff’s knowledge at para. 44:

In assessing the plaintiff’s state of knowledge, both direct and circumstantial evidence can be used. Moreover, a plaintiff will have constructive knowledge when the evidence shows that the plaintiff ought to have discovered the material facts by exercising reasonable diligence. Suspicion may trigger that exercise. (Crombie Property Holdings Ltd. v. McColl-Frontenac Inc., 2017 ONCA 16, 406 D.L.R. (4th) 252, at para. 42).

[55]      This court explained in Crombie that suspicion may trigger the due diligence obligation, but suspicion does not constitute actual knowledge. The full paragraph clearly explains the difference:

That the motion judge equated Crombie’s knowledge of possible contamination with knowledge of actual contamination is apparent from her statement that “[a]ll the testing that followed simply confirmed [Crombie’s] suspicions about what had already been reported on” (at para. 31). It was not sufficient that Crombie had suspicions or that there was possible contamination. The issue under s. 5(1)(a) of the Limitations Act, 2002 for when a claim is discovered, is the plaintiff’s “actual” knowledge. The suspicion of certain facts or knowledge of a potential claim may be enough to put a plaintiff on inquiry and trigger a due diligence obligation, in which case the issue is whether a reasonable person with the abilities and in the circumstances of the plaintiff ought reasonably to have discovered the claim, under s. 5(1)(b). Here, while the suspicion of contamination was sufficient to give rise to a duty of inquiry, it was not sufficient to meet the requirement for actual knowledge. The subsurface testing, while confirmatory of the appellant’s suspicions, was the mechanism by which the appellant acquired actual knowledge of the contamination.

[56]      Similarly, in Kaynes v. BP p.l.c., this court held that knowledge of allegations in pleadings does not, without more, constitute actual knowledge of one’s claim. […]


[59]      These examples draw out an important distinction from Grant Thornton: actual knowledge does not materialize when a party can make a “plausible inference of liability.” Rather, actual knowledge materializes when a party has “the material facts upon which a plausible inference of liability on the defendant’s part can be drawn” [emphasis added]. While class counsel may have had reason to suspect that Bank of America, Merrill Lynch and Morgan Stanley were part of the conspiracy, that suspicion was not actual knowledge. The motion judge erred in law by finding actual knowledge.

[64]      The effect of s. 5(1)(b) is to impose an obligation of due diligence on those who have reason to suspect that they may have a claim, but who do not yet have actual knowledge of the material facts giving rise to that claim: Crombie, at para. 42. Where potential plaintiffs sit idle or fail to exercise due diligence, the limitation period will commence on the date that the claim would have been discoverable had reasonable investigatory steps been taken. In other words, it is the date when the potential plaintiffs have constructive, as opposed to actual knowledge of their claim: Grant Thornton, at para. 44.

[65]      A court determining this issue will require evidence of how the material facts could reasonably have been obtained more than two years before the motion to add was brought: Mancinelli, at paras. 28, 31; Morrison v. Barzo, 2018 ONCA 979, at paras. 61-62.


The decision also includes an interesting if somewhat esoteric addition to s. 5(1)(a)(iv) appropriateness jurisprudence. A proceeding can be an appropriate remedy only if the circumstances give rise to a legally recognised cause of action on which to base the proceeding:


[37]      With respect to criterion (iv)[6], a proceeding would only be appropriate if the circumstances give rise to one or more legally recognized causes of action on which to base the proceeding. The wrong must have a legally recognized remedy. It is only in this sense – that legal recourse must be appropriate to address a loss caused by the proposed defendant’s act or omission – that the term “claim” has any legal specificity.

I expect the court assumed this to be self-evident, and perhaps it is. But it has a curious implication. Because a novel cause of action is, by definition, not legally recognised, it follows that a claim based on a novel cause of action is never discoverable. If a claim isn’t discoverable, the basic limitation period will never begin. Accordingly, only the ultimate limitation period could bar an action based on a novel claim.

Lastly, the decision contains a comprehensive statement of the law of amending a pleading to advance a new claim after the expiry of the limitation period.


[40]      These cases make it clear that it is the pleading of the facts that is key. If a statement of claim pleads all the necessary facts to ground a claim on more than one legal basis, and the original statement of claim only asserts one of the legal bases – that is, one cause of action based on those facts – the statement of claim can be amended more than two years after the claim was discovered to assert another legal basis for a remedy arising out of the same facts – that is, another cause of action. This is because it is only the discovery of the claim, as defined in the Limitations Act and the case law, that is time barred under s. 4, not the discovery of any particular legal basis for the proceeding.

[41]      In the textbook The Law of Civil Procedure in Ontario, Paul M. Perell & John W. Morden 4th ed. (Toronto: LexisNexis Canada, 2020), at pp. 220-21, the authors explain when an amendment will be allowed in the following passage:

A new cause of action is not asserted if the amendment pleads an alternative claim for relief out of the same facts previously pleaded and no new facts are relied upon, or amount simply to different legal conclusions drawn from the same set of facts, or simply provide particulars of an allegation already pled or additional facts upon which the original right of action is based… Thus, where a limitation period has run its course, allowing or disallowing the amendment depends upon whether the allegations of the proposed amendment arise out of the already pleaded facts, in which case the amendment will be allowed, but if they do not the amendment will be refused. An amendment of a statement of claim to assert an alternative theory of liability or an additional remedy based on facts that have already been pleaded in the statement of claim does not assert a new claim for the purposes of s. 4 of the Limitations Act. [Citations omitted.]

[42]      In Klassen v. Beausoleil, 2019 ONCA 407 at para. 30, this court instructed that the application of this test should not be stringent or overly technical:

In the course of this exercise, it is important to bear in mind the general principle that, on this type of pleadings motion, it is necessary to read the original Statement of Claim generously and with some allowance for drafting deficiencies.

Ontario: Court of Appeal on amending to add a new cause of action

In Polla v. Croatian (Toronto) Credit Union Limited, the Court of Appeal summarised the principles of amending to add a cause of action after the presumptive expiry of the limitation period:

[31]      The trial judge’s conclusion that the proposed amendment made a new claim is a legal determination, which is subject to the “correctness” standard of review on appeal: see Blueberry River First Nation v. Laird2020 BCCA 76, 32 B.C.L.R. (6th) 287, at paras. 20-21Strathan Corporation v. Khan2019 ONCA 418, at paras. 7-8. Her conclusion that the limitation period had expired is a determination of mixed fact and law, that was based in this case on a finding of fact as to when the appellant ought to have known about the new misrepresentation, and reviewable on a standard of “palpable and overriding error”: see Longo v. MacLaren Art Centre2014 ONCA 526, 323 O.A.C. 246, at para. 38. The same deferential standard of review applies to the refusal of an amendment based on an assessment of prejudice: Tuffnail v. Meekes2020 ONCA 340, 449 D.L.R. (4th) 478, at para. 120, leave to appeal refused, [2020] S.C.C.A. No. 269.

[32]      The general rule respecting the amendment of pleadings is that an amendment shall be granted at any stage of a proceeding on such terms as are just, unless prejudice would result that could not be compensated for by costs or an adjournment: Rules of Civil Procedure, R.R.O. 1990, Reg. 194, r. 26.01. The expiry of a limitation period in respect of a proposed new claim is a form of non-compensable prejudice, where leave to amend to assert the new claim will be refused: Klassen v. Beausoleil2019 ONCA 407, 34 C.P.C. (8th) 180, at para. 26.

[33]      There is no real dispute between the parties about the applicable test. In 1100997 Ontario Limited v. North Elgin Centre Inc.2016 ONCA 848, 409 D.L.R. (4th) 382, this court observed that an amendment to a statement of claim will be refused if it seeks to assert a “new cause of action” after the expiry of the applicable limitation period. As this court explained, at para. 19, in this context, a “cause of action” is “a factual situation the existence of which entitles one person to obtain from the court a remedy against another person” (as opposed to the other sense in which the term “cause of action” is used – as the form of action or legal label attached to a claim: see the discussion in Ivany v. Financiere Telco Inc.2011 ONSC 2785, at paras. 28-33).

[34]      The relevant principles are summarized in Paul M. Perell & John W. Morden, The Law of Civil Procedure in Ontario, 4th ed. (Toronto: LexisNexis Canada, 2020), at pp. 220-21, as follows:

A new cause of action is not asserted if the amendment pleads an alternative claim for relief out of the same facts previously pleaded and no new facts are relied upon, or amount simply to different legal conclusions drawn from the same set of facts, or simply provide particulars of an allegation already pled or additional facts upon [which] the original right of action is based.

This passage has been cited with approval by this court. See 1100997 Ontario Limited, at para. 20Davis v. East Side Mario’s Barrie2018 ONCA 410, at para. 32, and Klassen, at para. 29.

[38]      In conducting this assessment, the court must read the pleadings generously in favour of the proposed amendment: Klassen, at para. 30Rabb Construction Ltd. v. MacEwen Petroleum Inc.2018 ONCA 170, 29 C.P.C. (8th) 146, at para. 8. The existing pleadings, together with the proposed amendment, must be considered in a functional way – that is, keeping in mind that the role of pleadings is to give notice of the lis between the parties. As such, the question in this case is whether the respondents would reasonably have understood, from the Amended Statement of Claim and the particulars provided on discovery, that the appellant was pursuing a claim in respect of the matter addressed by the proposed amendment.

Ontario: Divisional Court on the outcomes of an amendment motion

Sirotek v. O’Dea contains terrifically clear guidance from the Divisional Court on the potential outcomes of an amendment motion opposed on the basis of a limitations defence.  The key point is that when the court grants leave to amend because the new claim is timely, that finding must be included in the formal order:

[5]               Where a claim is dismissed on the basis of a limitations defence, the result is a final order, appealable as of right.  No motion for leave to appeal is required.

[6]                Where a motion to amend is granted on the basis that there is no genuine issue of fact and law in dispute that could result in a limitations defence succeeding, the result is again a final order, appealable as of right.  No motion for leave to appeal is required: the limitations issue has been decided against the defendant on a final basis.

[7]               Where a motion for leave to amend a claim is granted on the basis that there remain genuine issues of fact and law in dispute as to whether a limitation defence is available, or where summary judgment is dismissed on the basis that there is a triable issue in respect to a limitations defence, then the order is interlocutory, and the appeal lies to this court with leave.

[8]               It is axiomatic that an appeal is taken from the impugned order and not from the reasons given for making the order.  In the context of a motion involving a limitations argument, where the order does not finally dispose of a limitations defence, then the order is interlocutory and the limitations defence is available to the defendant at trial.  The trial judge is not bound by the views of the motions judge on the limitations argument (if any).  Appeal rights on the final disposition of a limitations defence accrue when a final disposition is ordered.

[9]               An argument advanced on this motion for leave to appeal is that the motion judge erred in law in finding that the proposed amendments do not include new causes of action.  In fact, he made no such finding.  His decision therefore does not, as the moving parties assert, “in effect create a new carve-out in the application of the Limitation Act”.

[10]           Rather, the order from which leave is sought to appeal grants a pleading amendment without reference to a limitations defence.  While it is always preferable for the parties to address with the court whether the order is made without prejudice to a limitation defence being pleaded and raised at trial, where this is not done, it does not automatically follow that the limitation defence has been finally disposed of.

[11]           In the circumstances of this case, it is therefore open to the defendants to plead that defence in response to the amended claim.

Ontario: the limitations implications of withdrawing a claim

Curtis v. The Bank of Nova Scotia is a recent authority for the principle that removing a claim from a pleading causes the limitation period to continue running.  A plaintiff can’t reintroduce the claim if the limitation period has expired:

[22]       Mr. Curtis’ present Further Fresh As Amended Statement of Claim contains a series of paragraphs concerning what Mr. Curtis calls “bad faith breach of contract.” Having reviewed these paragraphs, I have concluded that they are primarily a reintroduction of the wrongful and constructive dismissal claim Mr. Curtis voluntarily removed from his pleading in January, 2016 almost four years ago. As such, its reintroduction at this point represent a violation of the two year limitation period under the Limitations Act, namely the introduction of a cause of action long after the expiration of the limitation period. Whether Mr. Curtis originally pleaded this cause of action is immaterial. He removed it in January, 2016, four years ago, and cannot now reintroduce it.

Ontario: the timing of amendments, and some words on laches

The Superior Court in Barker v. Barker is perhaps the most extreme example of an eleventh-hour motion to amend to plead discoverability.  The plaintiffs moved in the third week of trial to amend their Statement of Claim to plead reliance on ss. 5 and 16 of the Limitations Act in response to the defendants’ limitations defence (the decision is silent on why the plaintiffs chose to amend their Statement of Claim rather than file a Reply).  Justice Morgan didn’t find that the delay was fatal to the motion:

[8]               Whether or not the motion to amend would have been better brought before trial began rather than in its third week, what is clear is that the limitations issues, including as the Court of Appeal says, the application of section 16(1)(h.2) and the doctrine of discoverability, come as no surprise to the Defendants. They knew these issues were raised by the Plaintiffs in the 2017 motion before Perell J. Plaintiffs’ counsel has reproduced in their motion record copies of the factums from the 2017 motion, where these issues were argued for many paragraphs by both sides. As indicated above, the Defendants all knew that the 2018 judgment of the Court of Appeal had specifically reserved these issues for a later date, mentioning the trial itself as the likely time for canvassing section 16(1)(h.2) and discoverability.

[9]               Although mid-trial pleadings amendments are not encouraged as a matter of case management, Rule 26.02(c) provides that a pleading may be amended at any time, without limitation, with leave of the court. Moreover, the amendment rule is written in mandatory language. Rule 26.01 provides that, “On motion at any stage of an action the court shall grant leave to amend a pleading on such terms as are just, unless prejudice would result that could not be compensated for by costs or an adjournment.” Accordingly, a party seeking to prevent a pleading from being amended “must establish a link between the non-compensable prejudice and the amendment. It must show that the prejudice arises from the amendment”: Iroquois Falls Power Corp. v Jacobs Canada Inc.2009 ONCA 517 (CanLII), at para 20.

The decision is also noteworthy for its consideration of the role of discoverability in a laches analysis.  It is impossible to assess the impact of delay in suing without knowing when the plaintiff first ought to have known of the claim:

[25]           Embedded in this argument is the idea that different questions would be asked in an equitable laches case than in a statutory limitation case. More specifically, it assumes that discoverability, which is an integral part of a limitation period analysis both at common law and under statute, is not at issue in a laches analysis. That sounds somewhat plausible at first blush – after all, the equitable doctrine of laches is, like all doctrines of equity, related to but different in nuance from limitation periods as its nearest relative at law. Limitation periods are hard numerical rules while laches is a principle that requires a weighing of the competing equities: Manitoba Metis Federation Inc. v Canada (Attorney General)2013 SCC 14 (CanLII)[2013] 1 SCR 623, at paras 145-6. That difference, however, is not always as substantive as it may appear.

[26]           Almost a century ago, English legal scholar John Brunyate stated, “since delay by a plaintiff who has been ignorant of his right of action will not amount to laches, we should expect that…time will not run until the plaintiff is aware of his right of action.” Limitation of Actions in Equity (London: Stevens & Sons, 1932), c. 2, cited approvingly in M(K) v M(H)1992 CanLII 31 (SCC)[1992] 3 SCR 6. We need not delve into legal history to see that that logic makes sense. It would be impossible to evaluate the equities of a delay in bringing an action without knowing when the Plaintiff first realized he or she had been wronged.

[27]           In fact, the weighing of equities in a laches analysis specifically involves asking whether the claimant has acquiesced in the delay, which in turn involves evidence of the claimant’s state of mind and level of knowledge of the facts on which the cause of action is premised: Manitoba Metis Federation, at para 147. One can’t acquiesce in something one hasn’t discovered. It is little surprise, therefore, that the Supreme Court of Canada has indicated that the equitable doctrine of laches essentially mirrors the common law doctrine of discoverability: “It is not enough that the plaintiff knows of the facts that support a claim in equity; she must also know that the facts give rise to that claim”: M(K)supra, citing Re Howlett[1949] Ch. 767.

[28]           The Supreme Court in M(K) has specifically confirmed with respect to discoverability and laches that “both doctrines share the common requirement of knowledge on the part of the plaintiff.” The indicia of that knowledge – what did the Plaintiff know with respect to the alleged wrongs and his legal rights and when did he know it – will be the subject of discovery under both rules. It defies logic and the nature of the two very similar legal principles to say that a Defendant knew full well he had to discover on the issue of laches, but that he is greatly disadvantaged to now learn that he also had to discover on the issue of discoverability. The information sought and the questions asked will be virtually the same.

This analysis came in the context of a rather astonishing (and unsuccessful) argument by the Crown.  It denied having notice that discoverability was in issue despite having asked questions about discoverability on examination for discovery.  The Crown explained this contradiction by throwing a junior under the bus: apparently, the junior went rogue and asked the discoverability questions without instructions:

[19]           Turning to the discoverability doctrine, Defendants’ counsel contend that they have not had an opportunity to examine the Plaintiffs for discovery on the discoverability issue. They submit that at this late date, with the trial already underway, the motion to amend must either be dismissed outright or granted together with an adjournment of the trial so that further discovery can be conducted. Otherwise, they say, they are made to essentially defend a trial by ambush.

[20]           Counsel for the Plaintiffs responds with some incredulity. Plaintiffs’ motion record contains over a thousand pages of discovery transcripts in which the discoverability issue was explored with various Plaintiffs by Defendants’ counsel. Plaintiffs’ counsel point out that Defendants’ counsel canvassed everything from the dates that the Plaintiffs first contacted their present counsel, to previous complaints and law suits brought by any number of Plaintiffs, to the Plaintiffs’ awareness of and access to duty counsel while at Oak Ridge in the 1970s, to the letter writing campaigns engaged in by several of the Plaintiffs over the decades seeking to put a stop to the kind of acts in issue in this litigation. In addition, in the affidavits sworn by each of the Plaintiffs for the 2017 motion, and which by agreement of the parties now form part of the trial record, the Plaintiffs each provide information on the dawn of this case and how and when they personally became involved or realized that they could engage in a legal action.

[21]           Counsel for the government of Ontario at discoveries asked a number of the Plaintiffs for undertakings with respect to these issues, and followed up on those requests by sending Plaintiffs’ counsel an undertakings chart listing and describing each of the outstanding answers. The chart divided the outstanding undertakings into three categories, listing each of the undertakings as going to either “Liability”, “Damages”, or “Discoverability”. The label of this third category was not a Freudian slip; a perusal of the undertakings falling under this heading reveals precisely the kind of questions one would ask in order to unearth the opposing side’s discoverability position. Various Plaintiffs responded by indicating when in the past they learned about, and with whom and when in the past they had spoken about, the prospect of a law suit relating to their Oak Ridge experiences.

[22]           It is not surprising that Defendants’ counsel asked these questions. Discoverability, as Perell J. and the Court of Appeal pointed out, has long been an issue to be addressed in the case.

[23]           Defendants’ counsel responds by conceding that all of those questions were indeed asked, but says that they were for the most part meant to address the issue of laches as it pertains to the equitable claim of breach of fiduciary duties. It is the Defendants’ position that discoverability under the Act or at common law is a response to a defense which places an onus on the Plaintiff, and so it did not have to be canvassed at discoveries (or addressed at trial) if the Plaintiff did not specifically plead it.

[24]           At the same time, it is the Defendants’ position that with respect to the claim of breach of fiduciary duties the doctrine of discoverability does not apply either at common law or under the pre-Act limitations statutes in force in Ontario, but that the equitable doctrine of laches applies. Defendants’ counsel concedes that the onus is on the Defendant to establish the unfair delay on which the laches principle is premised. Accordingly, counsel for the Defendants explains that in their view, discoverability does not have to be explored in pre-trial examinations if the Plaintiff has not bothered to plead it, but laches has to be explored because it is clearly relevant and the Plaintiff need not plead it.

[29]           Interestingly, counsel for the Defendants conceded in argument that examinations on the issue of discoverability were in fact conducted with respect to 7 of the 28 Plaintiffs. Defendants’ counsel’s explanation for this is that, apparently, a very diligent young lawyer for the government of Ontario conducted the discoveries on those individual Plaintiffs, and was foresightful enough to pose questions exploring the discoverability issue. As for the rest of the individual Plaintiffs, other lawyers on the Defendants’ counsel team conducted those discoveries and the discoverability questions were not asked. Accordingly, the Defendants are not seeking to eliminate the doctrine of discoverability from the analysis of the limitation period with respect to 7 of the 28 Plaintiffs, but are seeking to eliminate it with respect to the remaining 21 Plaintiffs.

[30]            With respect, this position is not tenable. In the first place, counsel for Ontario asked for undertakings regarding discoverability from 13 of the Plaintiffs. If only 7 Plaintiffs were questioned about discoverability, how is it that undertakings were extracted from 6 more of them? Perhaps others on the Defendants’ counsel team were more foresightful and diligent than they have been given credit for.

[31]           But that is only part of the point. If the Defendants’ position is to be taken seriously, the young lawyer who supposedly on his or her own asked about facts going to the discoverability issue would have been fishing for information that, in the Defendants’ view, he or she had no right to ask about. Not surprisingly, Plaintiffs’ counsel did not object to this line of questioning and provided answers that now satisfy the Defendants such that they are not discounting the discoverability doctrine with respect to those 7 deponents. What was wrongful from the Defendants’ point of view when it was done has suddenly become rightful now that it helps explain some of the discoverability questions which the Defendants did in fact explore with the Plaintiffs.

[32]           Furthermore, if one lawyer on the Defendants’ team knew about the discoverability doctrine, they all knew about the discoverability doctrine. In order to put an opponent on notice in litigation, one conveys the notice to opposing counsel – any number of them or any one of them will do. If one member of a law firm of record has notice, or one member of the Ministry of the Attorney General is aware of an issue in the action, they all are presumed to have notice and be aware of the issue. The young lawyer who asked discoverability questions is not being presented as a rogue acting beyond his retainer; quite the opposite. He is being presented as a perhaps more thorough or diligent version of all the other Defendants’ lawyers.

Ontario: the timing of amendments to plead discoverability

Marvelous Mario’s Inc. et al. v. St. Paul Fire And Marine Insurance Co.  provides authority for the principle that an amendment to plead discoverability is available at any time:

[52]           The plaintiffs’ pleading is silent as to discoverability. Recognizing the gap in their pleading, the plaintiffs have moved for an order allowing them to amend their pleading to plead discoverability. St. Paul takes no position on the motion. Rule 26.01 of the Rules of Civil Procedure, R.R.O. 1990, Reg. 194allows for an amendment to be made at any time, even after the conclusion of trial: Hardy v. Herr, 1965 CanLII 225 (ON CA)[1965] 2 O.R. 801 (Ont. C.A.), at para. 2. Discoverability was an issue thoroughly canvassed at trial. I see no prejudice to St. Paul in granting the amendment. Accordingly, the plaintiffs’ motion to amend their statement of claim to plead discoverability is granted.

All of that said, it’s worth noting that the facts setting up a discovery argument are properly pleaded in reply.

Ontario: remember the amendment principles

Master Muir provides a helpful summary of amendment principles in Concord Adex Inc. v. 20/20 Management Limited:

[20]           The law in relation to motions seeking leave to amend a pleading is well settled and was not seriously in dispute on this motion. The applicable principles are summarized in my decision in Greenwald v. Ridgevale Inc.2016 ONSC 3031 (CanLII)2016 ONSC 3031 (Master). At paragraph 21 of Greenwald I set out those factors as follows:

• the amendments must not result in prejudice;

• the amendments must be legally tenable;

• the amendments must comply with the rules of pleading;

• a motion to add a party must meet all of the requirements of a motion under Rule 26.01;

• the addition of the party should relate to the same transaction or occurrence;

• the addition of the party should not unduly delay or complicate the hearing;

• the addition of a party will not be permitted if it is shown to be an abuse of process.

It is useful to keep these in mind when considering whether a motion to add a party of the presumptive expiry of the limitation period.

There is also a reminder that standard of discovery applicable when determining whether to add a proposed defendant after the presumptive expiry of the limitation period is reasonable discovery, not possible discovery:

[47]           With respect to all of these arguments it is important to emphasize that it is reasonable discoverability and not the mere possibility of discovery that triggers a limitation period. See Crombie Property Holdings Ltd. v. McColl-Frontenac Inc.2017 ONCA 16 (CanLII) at paragraph 35; leave to appeal refused, 2017 SCCA No. 85. The proposed defendants appear to be holding the plaintiffs to a standard of perfection. That is simply not the test.

Ontario: Stopping time when adding a new claim to a proceeding


A limitations practice tip—when amending a pleading to add a new claim, it’s the filing of the motion record that stops time running, not service of the motion record.  Master Albert recently made this point in Becerra v. Ronchin:


41)  The limitations clock does not stop running until a proceeding is launched. In the case of a motion to amend a pleading, the proceeding is launched either when the motion record is served (arguably) or more correctly when the motion record is filed with the court.  This is akin to the issuance of an action or application stopping the limitations clock where a plaintiff is launching a fresh proceeding. Service of an intention to issue a proceeding prior to issuance does not initiate the proceeding. Similarly, service of a notice of motion together with a without prejudice letter and without a motion record does not constitute the launching of a proceeding to amend a pleading in an existing action.

Ontario: Is it really a new cause of action?

You can’t amend a claim to assert a new cause of action if the cause of action is statute-barred.  The question is, when’s an amendment a new cause of action?

In Beauchamp v. Gervais, Justice Dunphy sets out the following test:

[23]           The preceding authorities establish that in order to qualify as something other than a new cause of action the proposed amendments must, in substance, be: (i) an alternative claim for relief, or a statement of different legal conclusions based on no new facts or not going beyond the factual matrix from which the original claim arose; (ii) better particulars of the claims already made; (iii) a correction of errors in the original pleading; or (iv) the assertion of a new head of damage arising from the same facts. If the amendments cannot be characterized in one of these ways, the amendments should not be permitted, in order to not deny a defendant the right to rely upon a limitations statute.

This paragraph follows a lengthy summary of the relevant jurisprudence that’s worth reading if you’re considering the issue.