A Personal Starting Point: Being Sued as a Lawyer

Over the course of a long career in personal injury litigation, I have been sued more than once, including one time up to the end of a full-blown trial, and as a result, I certainly know about that on which I am about to speak. Mine is not an unusual experience. Any lawyer who runs a high-volume practice, particularly in personal injury, eventually becomes a target. The reason is not mysterious. There is insurance. Where there is insurance, there is perceived recoverability, and where there is perceived recoverability, there will be claims.

What is perhaps less widely appreciated is how rarely those claims succeed in any meaningful way. In my own experience, they have almost invariably been successfully defended to dismissal or beyond, in one case all the way to the Supreme Court of Canada^[1]. That is not because lawyers are immune from negligence. They are not. It is because the legal test for solicitor’s negligence is demanding, and because insurers retain experienced defence counsel who understand how to dismantle these claims methodically and effectively.

Ontario malpractice data tells a fairly blunt story. Fewer than 20% of claims result in any payout, and even where liability is established, recovery is often modest. The picture becomes even clearer when matters proceed to litigation, where Ontario lawyers’ errors and omissions insurer LawPRO^[2] successfully defends approximately 70% of cases that go to court. And of the claims that do result in payment, fewer than 10% exceed $100,000, underscoring how uncommon it is for these cases to generate significant damages^[3]. Set against that is the broader context that thousands of claims are reported annually in Ontario. For example, there were 3,758 claims in 2024 alone^[4], yet the most common underlying issues are not dramatic errors in legal judgment, but far more routine problems such as communication breakdowns and missed deadlines^[5]. The result is a body of litigation that is highly fact-driven, difficult to prove, and far less likely than many assume to produce substantial recovery.

That reality provides the right starting point for any discussion of lawyers’ liability. The exposure is real. The risk is constant. But the threshold for success is high, and properly defended cases often fail.

The Legal Framework: Solicitor’s Negligence in Ontario

At its core, a claim against a lawyer is simply a negligence claim, but one shaped by the unique context of the solicitor-client relationship. The plaintiff must establish the familiar elements of duty, breach, causation, and damages, but each of those elements takes on a particular meaning when applied to legal professionals.

The existence of a duty of care is rarely controversial. Once a solicitor-client relationship is established, the duty follows as a matter of course. The real battleground lies in the standard of care and in causation.

The standard expected of a lawyer is not perfection. It is the standard of a reasonably competent solicitor in similar circumstances. Courts have consistently emphasized that the practice of law involves judgment calls, strategic decisions, and imperfect information. The law does not punish every error. It only attaches liability where the lawyer’s conduct falls below what would reasonably be expected of a competent practitioner.

This principle is reflected in leading Ontario jurisprudence, including Central Trust Co. v. Rafuse, [1986] 2 S.C.R. 147 (CanLII)<^[6], where the Supreme Court of Canada confirmed that solicitors may be liable in both contract and tort, but only where their conduct falls below the applicable standard of care. The case arose out of a mortgage transaction in which solicitors employed a form of security that proved legally ineffective, leaving the lender without the protection it believed it had bargained for and ultimately exposed to loss. The borrower defaulted, and the defect in the security came to light only after the fact, prompting the lender to pursue a negligence claim against the solicitors. The decision remains foundational, particularly in its recognition that professional liability must be assessed against the realities of legal practice, not in hindsight.

The “Case Within the Case”: Proving Causation

Even where a breach of the standard of care is established, plaintiffs face a second and often insurmountable hurdle: causation.

In solicitor’s negligence, causation is typically assessed through what is commonly referred to as the “case within a case.” The plaintiff must demonstrate not only that the lawyer was negligent, but that the underlying matter would have produced a better outcome but for that negligence.

In Central Trust Co. v Rafuse, the Supreme Court made clear that it is not enough to point to an error. The plaintiff must establish, on a balance of probabilities, that the loss flowed from conduct falling below the standard expected of a reasonably competent solicitor. In practical terms, this often requires the Court to assess what would have occurred but for the negligence, effectively reconstructing the underlying transaction or litigation, not as speculation, but as a proven, probable outcome grounded in evidence.

In practical terms, this is where many claims fail. It is one thing to allege that a limitation period was missed or that advice was incomplete. It is another to prove that the underlying claim would have resulted in a tangible recovery. Courts are rightly cautious about awarding damages based on hypothetical outcomes.

The Role of Expert Evidence

The standard of care in solicitor’s negligence cases is not something the court typically determines in a vacuum. It is almost always informed by expert evidence. I wrote a Substack last year on this very topic, “When You Sue a Professional, Bring an Expert—or Don’t Bother”.<^[7]The general rule is that you need expert evidence. Ontario’s Court of Appeal has made this point repeatedly.

In Krawchuk v. Scherbak 2011 ONCA 352^[8], a purchaser relied on a seller’s property-information form and a dual-agent realtor to buy a house that later revealed serious structural defects. On appeal, the agent and brokerage were held liable alongside the vendors for failing to verify the sellers’ assurances or recommend an inspection. The Court held that, as a general matter, a trial judge should not determine a professional standard of care without expert evidence. Why? Because the “standard” in a specialized field is proved, not intuited. Courts shouldn’t become their own experts, subject to two narrow exceptions. First, when the issue is non-technical, the sort of thing a layperson understands, courts may dispense with experts. Second, when the defendant’s conduct is egregious, that is so plainly below any acceptable standard that you don’t need someone in the guild to say so, expert evidence may be unnecessary. Both exceptions come from Krawchuk and are applied sparingly.

There are some recent examples of the Court applying Krawchuk.  In Yormak v. LeDroit 2022 ONSC 4615^[9], a former client who had lost a partial summary-judgment motion in litigation over unpaid tax debts sued his lawyers for negligent strategy. The Court dismissed the claim, holding that the absence of standard-of-care expert evidence was fatal and reiterating that judges are not free to act as their own experts in solicitor’s-negligence cases. In Hopkins v. Murphy 2024 ONSC 3698^[10], the Court dismissed a negligence claim alleging a lawyer’s settlement advice fell outside the reasonable range. The plaintiff ran into two walls, specifically no standard-of-care expert and no “trial within a trial” to show what the underlying action would likely have yielded. The decision is a pragmatic reminder that expert opinion anchors both liability and the “range of reasonable choices” analysis.

Even at modest monetary limits, the rule bites. In Estate of Thankamma Mathi v. Juriansz 2024 ONSCSM 10495^[11], the Small Claims Court refused to second-guess a solicitor’s capacity assessment, conflict/ILA advice, or protective steps without expert evidence, none of which qualified as “non-technical,” and nothing about the conduct was “egregious” on its face.

The requirement for expert evidence in professional negligence cases isn’t going anywhere. Standards of professional practice evolve inside disciplines. What’s “careful” conveyancing in a conflict-tinged transfer? What’s “reasonable” case-assessment before recommending settlement? What due-diligence steps are “usual or customary” for a realtor confronted with red-flag defects? Those aren’t gut calls. They’re proved through people who actually do the work, subject to cross-examination, not through judicial instinct or counsel rhetoric.

That’s exactly why Krawchuk’s framework has stuck and spread. An experienced lawyer, usually practising in the same area as the defendant, is called to give opinion evidence on what a reasonably competent solicitor would have done in the circumstances. That evidence can be decisive. Without it, many claims cannot get off the ground. Ontario courts have consistently recognized that, except in the clearest cases, expert evidence is required to establish both the standard of care and any alleged breach. The practice of law is too nuanced and context-specific for judges to rely solely on their own intuition about what a lawyer should have done. This creates a practical barrier for plaintiffs. Retaining a credible expert is costly, and the expert must be prepared to say not only that the defendant lawyer erred, but that the error fell below the professional standard. Many potential claims do not survive that scrutiny.

Judgment, Not Perfection

One of the most important and often misunderstood features of solicitor’s negligence law is the protection afforded to reasonable professional judgment.

Lawyers are required to act competently, diligently, and in their client’s best interests. They are not, however, guarantors of outcomes. The law recognizes that legal practice involves uncertainty, incomplete information, and the need to make strategic decisions in real time. Courts have consistently resisted the invitation to second-guess those decisions with the benefit of hindsight.

This principle is well illustrated by the Ontario Court of Appeal’s decision in Hall v. Bennett Estate, 2003 CanLII 7157 (ON CA)^[12]. The case arose from a solicitor’s decision not to prepare a will for a terminally ill client whose capacity was in question. Although the trial judge found the solicitor liable, the Court of Appeal overturned that decision, emphasizing that the relevant inquiry was not whether the client in fact had testamentary capacity, but whether a reasonably prudent solicitor could have concluded that he did not. The distinction is critical. Solicitors are not judged against the benefit of hindsight or the Court’s own assessment of the facts, but against what a competent practitioner could reasonably have decided in the circumstances at the time. On the evidence, the solicitor’s decision to decline the retainer fell within that range of reasonable professional judgment, and no liability followed.

That distinction matters. Many solicitor’s negligence claims are, at their core, disagreements with judgment calls. Without more, that is not enough.

Error Is Not Negligence

Closely related to this is a point that bears stating explicitly: not every mistake is negligence.

The standard of care is not perfection. It is reasonableness. The law accepts that competent lawyers can and do make errors, particularly in complex or fast-moving matters. Liability only arises where the conduct in question falls below the standard expected of a reasonably competent solicitor.

This is not a semantic distinction. It is the dividing line on which these cases turn. A missed argument, an unsuccessful strategy, or a decision that later proves unwise does not, in itself, establish liability. As the Ontario Court of Appeal made clear in Hall v. Bennett Estate, the question is not whether the lawyer’s decision was correct, but whether a reasonably prudent solicitor could have made that decision in the circumstances. If so, no negligence arises.

Ontario courts continue to apply that principle in practice. In Yormak, the court declined to second-guess litigation strategy, emphasizing that professional judgment, particularly in contested proceedings, falls within a range of reasonable choices. The fact that a strategy did not succeed was not enough.

The plaintiff must show that the lawyer’s conduct was not merely wrong, but outside the acceptable range of professional competence. Where reasonable lawyers could disagree, negligence will not be found.

Why Most Claims Fail

When viewed in practice, the outcome is not surprising. Solicitor’s negligence claims rarely fail for lack of an alleged error. They fail because the plaintiff cannot prove that the error made a difference.

By the time a claim reaches this stage, the plaintiff has already cleared one hurdle: identifying conduct said to fall below the standard of care, typically through expert evidence. But that is only the beginning. The real question is whether the outcome would have been materially better but for the lawyer’s conduct. That is where most cases collapse.

Ontario decisions reflect this pattern. In Hopkins, the claim failed not only for lack of expert evidence, but because the plaintiff could not establish what the underlying action would likely have produced. In Yormak, the absence of expert evidence on the standard of care was fatal at the outset. Even at the Small Claims level, courts have refused to relax these requirements. In Estate of Thankamma Mathi, the court declined to second-guess a solicitor’s conduct in the absence of expert evidence, reinforcing that these are not matters of common knowledge.

These cases are not outliers. They illustrate a consistent reality. The plaintiff must prove a breach of a demanding professional standard, overcome the protection afforded to reasonable judgment, and establish a better outcome on evidence, not inference. Each of those steps is difficult. Taken together, they are often insurmountable.

That is why most claims fail. Not because the allegation is implausible, but because the proof does not carry.

A Mediator’s Perspective

From a mediator’s standpoint, solicitor’s negligence cases present a distinct set of challenges.

They are rarely just about money. They engage issues of professional identity, judgment, and reputation. Plaintiffs often feel let down by someone they trusted. Lawyers, for their part, feel that their decisions are being unfairly second-guessed with the benefit of hindsight. Insurers approach the case through the lens of risk, precedent, and defensibility.

The cases that resolve are the ones where the parties can move past the question of who was “right” and engage with the practical realities of litigation risk. The cases that do not are often those where the analysis never gets beyond principle.

Closing Thoughts

Lawyer’s negligence is real, and no practising lawyer is immune from it. But the system is not designed to punish every mistake. It is designed to identify and compensate true departures from professional standards that cause real loss.

The law sets a high bar. The requirement for expert evidence, the rigor of the “case within a case,” and the protection afforded to reasonable judgment all operate as meaningful safeguards. Properly understood, these principles explain why so many claims fail, and why those that succeed tend to be the exception rather than the rule.

For those who practise in high-volume areas, being sued is, at some point, part of the landscape. The better approach is not to fear it, but to understand it.