One of the most consequential facts about medical malpractice litigation in Ontario is how the costs framework operates. Canadian civil litigation runs on a “loser pays” principle: the successful party in a contested action is, with limited exceptions, entitled to be reimbursed for a substantial portion of their legal costs by the unsuccessful party. The principle applies symmetrically. A plaintiff who wins a major malpractice trial can expect a costs order in the millions against the defendant physician (or the physician’s insurer). A plaintiff who loses can expect the same order, in the same magnitude, running the other way. The costs exposure is one of the structural realities of pursuing a malpractice case. It is one of the considerations I discuss with every prospective client at the outset.
Papineau v Romero-Sierra and Brisebois, 2025 ONSC 194, is the costs decision that followed the dismissal at trial of the plaintiff’s failure-to-diagnose Lyme disease claim. Justice H. Williams of the Ontario Superior Court of Justice released the costs decision on January 9, 2025. The trial decision (Papineau v Romero-Sierra, 2024 ONSC 6116) had dismissed the claim on multiple grounds. The costs decision awarded the successful physicians $957,893 in legal costs. That award was on top of the $100,000 previously ordered for costs thrown away due to an earlier adjournment. The total costs exposure for the unsuccessful self-represented plaintiff was therefore $1,057,893.
For prospective clients, this case is a useful illustration of why the question “should you sue” is at least as important as the question “can you sue.” The financial consequences of losing a malpractice trial are not theoretical. They are real, they are quantified at the dollar level by a court order, and they are enforceable. Where the plaintiff is self-represented, the consequence does not diminish; if anything, the absence of counsel often produces a record at trial that makes the costs exposure worse.
This post covers the costs decision and the broader framework for costs in Ontario civil litigation. The trial decision has its own case comment, which addresses the substantive medical malpractice analysis. The focus here is on the costs framework specifically.
The trial decision (in brief)
A brief summary of the trial decision is needed to make sense of the costs decision. For the full analysis see the trial decision case comment.
The plaintiff brought a malpractice action against two family physicians alleging that they had failed to diagnose Lyme disease. The trial proceeded over several weeks. The trial judge dismissed the action on multiple grounds. The grounds most relevant to the subsequent costs analysis:
Credibility findings against the plaintiff. Much of the plaintiff’s oral testimony was found to be unreliable. Some of it was found to be incredible. The trial judge identified specific aspects of the testimony that conflicted with the contemporaneous documentary record:
- The plaintiff insisted at trial that he had been bitten by a tick (the vector for Lyme disease). The contemporaneous emergency department records from the Kemptville District Hospital indicated that, in the days after the bite, the plaintiff himself reported believing he had been bitten by an insect, not a tick.
- The plaintiff had a rash at the time of his ED presentation. The defendant family physician (Dr. Brisebois) had assessed the rash and concluded it was cellulitis, not erythema migrans (the distinctive rash associated with Lyme disease).
- The plaintiff had never been definitively diagnosed with Lyme disease by a physician with access to all the relevant information. His Lyme disease diagnosis came from an American practitioner.
- Following the American diagnosis, the plaintiff was offered referrals to Canadian infectious disease specialists who could have confirmed or ruled out the diagnosis. He refused all offers of referral, on the basis that he already knew he had Lyme disease.
Improper conduct of the litigation at trial. The trial judge found that the plaintiff had conducted an aggressive personal attack on the defendant Dr. Romero-Sierra’s integrity and reputation during trial. While the trial judge did identify some contradictions in Dr. Romero-Sierra’s testimony, and noted that his chart was less than perfect, the attacks against him were “unfounded, unfair and particularly audacious” given that the plaintiff’s own foundational evidence had been found to be unbelievable.
Damages claim contradicted by contemporaneous evidence. The plaintiff testified about how Lyme disease had forced him to restrict his recreational, social, and sports activities. On cross-examination, he agreed that he had failed to mention a 7,000 kilometre motorcycle trip he had undertaken from Ottawa to Tuktoyaktuk in August 2019, after the alleged onset of his Lyme disease symptoms. He had documented the trip extensively on Facebook.
These findings are not unusual in unsuccessful plaintiff cases. What they show is the operational reality of a contested trial: the plaintiff’s evidence is tested against the contemporaneous documentary record, against the medical and expert evidence, against the witnesses called by the defence, and against the social media and other digital traces of the plaintiff’s actual functioning. Where the plaintiff’s case at trial does not hold up against this testing, the trial judge will reach findings of incredibility, and those findings can substantially affect the subsequent costs analysis.
The costs decision
The costs hearing proceeded after the trial decision. Justice Williams had to decide whether to order costs, in what amount, and on what scale.
The successful party. The defendant physicians were the successful party. The action against them had been dismissed in its entirety. Under the costs framework in Ontario civil litigation, the successful party is presumptively entitled to costs.
The amount sought. The defendants sought $957,893 in costs.
The amount awarded. Justice Williams accepted the defendants’ costs demand as “fair and reasonable” and ordered the full amount.
The pre-existing adjournment costs. On top of the $957,893, the plaintiff had previously been ordered to pay $100,000 in costs thrown away due to a previous adjournment. The pre-existing order remained outstanding. The total costs exposure was therefore over $1 million.
The reasoning. The trial judge identified the following considerations in support of the costs award:
- The credibility findings against the plaintiff (much of his testimony was unreliable or incredible)
- The aggressive and unfair attacks on the defendant’s integrity at trial
- The contradiction between the plaintiff’s damages testimony and the contemporaneous Facebook documentation
- The benchmark costs awards in other contested medical malpractice trials, all going the other way (plaintiff wins)
The benchmark costs cases cited by the trial judge are themselves of doctrinal interest. They include three significant plaintiff-success cases in the cluster:
- Denman v Radovanovic, 2023 ONSC 3621, aff’d 2024 ONCA 276 — $3,000,000 in costs after a 25-day medical negligence trial
- Hemmings v Peng, 2022 ONSC 6482 — over $4,000,000 in costs after a 42-day medical negligence trial
- Henry v Zaitlen, 2022 ONSC 3050 — $800,000 in costs after a 25-day medical negligence trial
The trial judge’s reasoning is implicit: if plaintiffs can receive $3-4 million in costs when they succeed against physicians in major malpractice trials, then $957,893 in costs to physicians when the plaintiff fails in a multi-week trial of the same kind is not excessive. The symmetry of the costs framework supports the amount. The detailed cluster treatment of the three plaintiff-success cases is available in the case comments on Denman v Radovanovic, Hemmings v Peng, and Henry v Zaitlen.
The costs framework in Ontario civil litigation
A more detailed treatment of the legal framework is useful because the costs question recurs in every contested malpractice trial.
The statutory authority. Section 131 of the Courts of Justice Act, R.S.O. 1990, c. C.43, gives the court discretion to award costs and to fix the amount. The discretion is broad. The court “may” award costs to or against any party.
The procedural framework. Rule 57.01 of the Rules of Civil Procedure, R.R.O. 1990, Reg. 194, lists the factors the court takes into account in exercising its discretion. The factors include:
- The amount claimed and the amount recovered
- The complexity of the proceeding
- The importance of the issues
- The conduct of any party that tended to shorten or lengthen unnecessarily the duration of the proceeding
- Whether any step in the proceeding was improper, vexatious, or unnecessary
- Whether any step was taken through negligence, mistake, or excessive caution
- A party’s denial or refusal to admit anything that should have been admitted
- Whether it is appropriate to award any costs or more than one set of costs where a party (i) commenced or continued separate proceedings for claims that should have been made in one proceeding, or (ii) in defending a proceeding, separated unnecessarily from another party in the same interest or defended by a different solicitor
- Any other matter relevant to the question of costs
The factor most engaged in Papineau was the conduct of the parties at trial, including the credibility findings and the unfounded attacks on the defendant.
Scales of costs. Ontario civil litigation operates on multiple scales of costs:
- Partial indemnity. The default scale for a successful party. Roughly covers 50-60% of the actual legal fees incurred.
- Substantial indemnity. A higher scale, typically awarded where the conduct of the unsuccessful party warrants it (for example, conduct that has unreasonably prolonged the proceeding, or where the unsuccessful party has rejected a reasonable Rule 49 offer). Roughly covers 75-90% of actual legal fees.
- Full indemnity. A rare scale, typically awarded only where the unsuccessful party’s conduct has been particularly egregious. Covers the full actual legal fees.
The scale awarded in Papineau is not explicitly identified in the decision excerpt, but the amount ($957,893) reflects a substantial award. Defence counsel’s actual fees in a multi-week medical malpractice trial typically run in the $1-2 million range. The Papineau costs award sits in the partial-to-substantial indemnity range.
The Rule 49 offer framework. Rule 49 of the Rules of Civil Procedure creates a structured incentive to settle. Where a party makes a written offer to settle at least seven days before the hearing of the proceeding, and the party obtains a judgment as favourable as or more favourable than the terms of the offer, the offering party is presumptively entitled to substantial indemnity costs from the date of the offer. The framework operates in both directions. A defendant who makes a reasonable settlement offer that the plaintiff rejects, and who then wins at trial, can be entitled to elevated costs.
The pre-trial costs. Costs thrown away due to adjournments, costs of motions, and costs of pre-trial steps can all be ordered at the time the relevant steps occur. The $100,000 in costs thrown away in Papineau was an example of this — the costs were ordered separately when the adjournment was granted, not at the end of the trial. The order remained enforceable and was added to the trial costs award.
Why malpractice trial costs are so high
The costs awards in modern Ontario medical malpractice trials are substantially higher than awards in many other categories of civil litigation. Several structural features explain this:
The expert evidence cost. Medical malpractice trials require expert evidence on standard of care, causation, and damages. Each side typically retains multiple experts — sometimes ten or more across all specialties involved. Each expert reviews voluminous records, prepares reports, and testifies at trial. The expert fees alone in a major malpractice trial typically run to several hundred thousand dollars per side.
The voluminous record. Medical records, hospital charts, imaging studies, lab results, and contemporaneous correspondence in a single malpractice case can run to thousands of pages. Counsel must review all of it, organize it for trial, and prepare to address each document with each witness. The hours involved are substantial.
The complexity of the issues. Medical and legal issues operate at the intersection of two technical fields. Counsel must understand both the underlying medicine and the legal framework that applies to it. Preparation for a malpractice trial is more intensive than for many other types of civil trial.
The duration of the trial. Modern Ontario malpractice trials run several weeks to several months. Hemmings v Peng (cited as a benchmark in Papineau) was a 42-day trial. The longer the trial, the more hearing-day costs accumulate.
The number of parties. Many malpractice cases involve multiple defendants (treating physicians, consulting physicians, hospitals, institutional bodies). Each defendant typically has separate counsel. Each set of counsel files separate factums, conducts separate cross-examinations, and seeks separate costs.
The cumulative effect: actual legal fees in a major Ontario malpractice trial routinely exceed $1-2 million per side. Costs orders that recover a substantial portion of those fees can run from several hundred thousand to several million dollars.
The self-represented litigant dimension
The plaintiff in Papineau was self-represented at trial. The self-representation does not reduce the costs exposure. The framework operates the same way regardless of whether the plaintiff is represented by counsel.
Several considerations on self-representation in medical malpractice:
Self-representation does not reduce defendant costs. The defendant’s costs are calculated based on what the defendant’s counsel actually billed (or would have billed). Whether the plaintiff was represented or not, the defence costs were incurred and are recoverable on the same scale.
Self-represented plaintiffs often have weaker cases at trial. Medical malpractice trials require expert evidence to establish standard of care and causation. Most plaintiffs cannot effectively engage experts on their own. The strategic decisions, the procedural compliance, the cross-examination of the defence experts, and the responsive evidence all require legal skill. A self-represented plaintiff in a complex malpractice case is at a substantial procedural disadvantage even if the underlying claim has merit.
Self-representation can also produce inadmissible or inflammatory conduct at trial. The trial judge in Papineau found that the plaintiff had launched “unfounded, unfair and particularly audacious” attacks on the defendant. Counsel for a plaintiff would have managed the trial conduct to avoid this kind of finding. Without counsel, the plaintiff’s conduct itself produced findings that informed the costs decision.
Self-representation by choice vs by necessity. Some plaintiffs choose to self-represent. Others self-represent because counsel they approached declined to take their case. Either way, the costs framework applies the same way. But the second category is also a signal: where multiple competent malpractice counsel have declined a case, that is information about the likely merits of the case. A self-represented plaintiff who is pursuing a case that experienced counsel have declined is often pursuing a case that does not have realistic prospects of success.
For prospective clients considering self-representation, the operational implication is clear: the financial risk of pursuing a malpractice case is the same whether you have counsel or not. The strategic disadvantage of being unrepresented is substantial. The combination of equal financial risk and reduced strategic capability typically produces worse outcomes for self-represented plaintiffs.
The chronic Lyme disease litigation pattern
A brief note on the substantive medical context, because the pattern recurs across this category of case.
Lyme disease (caused by the bacterium Borrelia burgdorferi, transmitted by certain ticks) is a real disease with well-established diagnostic criteria, treatment protocols, and clinical course. Acute Lyme disease is diagnosed using a combination of clinical findings (most distinctively the erythema migrans rash) and laboratory testing (the two-tiered serological testing protocol). Treated appropriately, most cases resolve fully.
A separate clinical phenomenon, variously called “chronic Lyme disease” or “post-treatment Lyme disease syndrome,” has been the subject of substantial controversy. Some patients report persistent symptoms attributed to Lyme disease beyond the acute treatment period. The Canadian medical community, the Centers for Disease Control and Prevention, and most national medical bodies do not recognize “chronic Lyme disease” as a distinct clinical entity diagnosable by clinical criteria alone, and they do not generally support the diagnostic and treatment frameworks used by some American clinicians who self-identify as “Lyme-literate” practitioners.
The disjunction between mainstream Canadian medical practice and the “Lyme-literate” practitioner community has produced a recurring litigation pattern. A patient develops chronic symptoms that they attribute to Lyme disease. The Canadian physicians they have seen have not diagnosed Lyme disease. They obtain a diagnosis from an American practitioner using non-standard criteria. They then commence malpractice action against the Canadian physicians for failure to diagnose. The trial proceeds with the Canadian medical community giving evidence that the diagnosis is not supportable on the available evidence, that the standard of care for Canadian family physicians was met, and that the plaintiff has not in fact been shown to have had Lyme disease in the first place. The action is typically dismissed.
The pattern is not specific to Lyme disease. Similar litigation patterns have occurred around chronic fatigue syndrome, fibromyalgia, mould-related illness, and various other clinical entities that occupy contested space between recognized medical practice and alternative or non-standard practice. The legal framework treats all such cases the same way: the plaintiff carries the burden of establishing the diagnosis on the balance of probabilities using the evidentiary standards applicable to medical malpractice. Where the plaintiff cannot meet that burden, the action fails on the threshold question of whether the disease being claimed actually existed.
The doctrinal point: a malpractice action for failure to diagnose requires the plaintiff to establish that the disease in question existed and that the physician’s failure to diagnose it fell below the standard of care. Where the existence of the disease is itself contested and not supported by mainstream medical evidence, the case typically fails at the first step.
Social media evidence in damages claims
A separate doctrinal point that emerges from Papineau is the use of social media as evidence in damages claims.
The plaintiff in Papineau described how Lyme disease had restricted his recreational, social, and sports activities. The defence cross-examined him on a 7,000 kilometre motorcycle trip from Ottawa to Tuktoyaktuk in August 2019 that he had documented on Facebook. He had not mentioned the trip in his examination-in-chief or in his pleadings. The contradiction between the damages testimony and the documented trip undermined the credibility of his damages claim and ultimately informed the costs analysis.
The framework is now well-established in personal injury and malpractice litigation:
- Public social media posts are admissible as evidence
- Defendants routinely review the plaintiff’s social media as part of investigation
- Contradictions between damages claims and social media evidence are particularly damaging because they can be presented contemporaneously and visually
- A plaintiff who has been claiming inability to engage in recreational activities and whose Facebook shows them engaging in those activities faces a credibility problem that often cannot be repaired at trial
For prospective clients: social media is part of the evidentiary record. Activities posted publicly during the relevant period can be expected to come up at trial. The discrepancy between damages testimony and contemporaneous social media documentation is one of the most common features of plaintiff credibility findings in modern personal injury and malpractice litigation.
Why this matters for prospective clients
The most important takeaway from Papineau is the financial risk dimension of pursuing a medical malpractice case. The risk is real, it is substantial, and it operates the same way regardless of whether the plaintiff is represented or self-represented.
Several practical points:
Costs are an essential consideration in deciding whether to pursue a case. A prospective client thinking about a malpractice case needs to understand that an unsuccessful trial can produce a costs order of several hundred thousand to several million dollars. This is not theoretical. It is the working reality of major malpractice cases.
Counsel typically structure malpractice retainers with this exposure in mind. Most experienced malpractice counsel work on a contingency basis where there are no fees unless the case is won. The contingency arrangement addresses the plaintiff’s exposure to their own counsel’s fees but does not address the exposure to the defendant’s costs if the case fails. Many firms also arrange for after-the-event insurance (sometimes called “adverse costs insurance”) to address the defendant-costs exposure. This is a structural feature of how plaintiff malpractice practice operates in Ontario.
Settlement discussions need to take costs exposure into account. A defendant’s settlement offer should be assessed against not just the expected damages but also the risk-adjusted costs exposure. A reasonable offer that the plaintiff rejects can produce subsequent Rule 49 cost consequences that effectively make the rejected offer the floor of the recovery.
Self-representation amplifies the risk. As discussed above, self-representation does not reduce the financial exposure and typically increases the procedural disadvantage. Where experienced malpractice counsel have declined to take a case, that is informational. Plaintiffs should weigh that information seriously before pursuing the case on their own.
For more on the general framework for evaluating whether a malpractice case is worth pursuing, see Suing for Medical Malpractice in Ontario: What You Need to Know and Six Common Misunderstandings About Medical Malpractice in Ontario. The costs framework is one of the most important practical considerations in deciding whether to proceed.
Cluster integration
The costs decisions cluster:
- Papineau v Romero-Sierra [costs] — $1M+ against an unsuccessful self-represented plaintiff
- Denman v Radovanovic [costs] — $3M to successful plaintiffs after 25-day informed consent trial
- Hemmings v Peng [costs] — over $4M to successful plaintiffs after 42-day obstetric anaesthesia trial
- Henry v Zaitlen [costs] — $800K to successful plaintiffs after 25-day delayed-diagnosis trial
The four cases together provide a quantitative anchor for the modern Ontario malpractice costs framework. Together they illustrate the symmetry of the framework (plaintiff wins produce defendant-paid costs; defendant wins produce plaintiff-paid costs) and the magnitude of exposure on either side.
The Papineau pairing:
- Trial decision — Papineau v Romero-Sierra (the substantive merits analysis)
- Papineau v Romero-Sierra (Costs) (this post — the costs decision)
The two posts work together as paired commentary on the same case.
The multi-ground dismissal pattern:
- Papineau trial decision — multiple grounds for dismissal
- Williamson v Y — multiple grounds (BC)
- Noel v Hawrylyshyn — multiple grounds (Ontario birth injury)
- Pellerin v Balfour — multiple grounds (BC appendicitis ED)
The cost benchmark cluster (plaintiff-success cases referenced as benchmarks in Papineau):
- Denman v Radovanovic — informed consent
- Hemmings v Peng — obstetric anaesthesia
- Henry v Zaitlen — delayed diagnosis of spinal dural arteriovenous fistula
NEW substantive practice area: the costs framework in Ontario medical malpractice.
Decision Date: January 9, 2025
Jurisdiction: Ontario Superior Court of Justice
Citation: Papineau v Romero-Sierra and Brisebois, 2025 ONSC 194 (CanLII)
Trial decision: Papineau v Romero-Sierra, 2024 ONSC 6116 (the underlying trial decision; subject of a separate case comment)
Disposition: $957,893 in legal costs awarded to the successful defendant physicians, in addition to $100,000 in costs thrown away due to a previous adjournment that had been ordered separately. Total costs exposure for the unsuccessful self-represented plaintiff: $1,057,893.
Key authorities cited: Denman v Radovanovic, 2023 ONSC 3621, aff’d 2024 ONCA 276; Hemmings v Peng, 2022 ONSC 6482; Sean Omar Henry v Dr. Marshall Zaitlen, 2022 ONSC 3050.
Applicable framework: Section 131 of the Courts of Justice Act, R.S.O. 1990, c. C.43, and Rule 57.01 of the Rules of Civil Procedure, R.R.O. 1990, Reg. 194.
