Ontario civil litigators have lived with an uncomfortable truth for years, that expert evidence often adds volume without adding clarity. One expert becomes two. Two become four. Soon enough, a courtroom fills with a “clown car” of highly qualified professionals offering carefully hedged opinions that align, almost perfectly, with the interests of the party who retained them. By the end, the trier of fact is left to choose between polished but incompatible narratives that frequently cancel each other out.

In mediations, I see this weekly.

The Final Policy Report^[1] of the Civil Rules Review Working Group calls this out directly, identifying “expert bias” and concerns about hired guns as a systemic problem in need of structural reform, not polite reminders about independence. What follows in the report is not a symbolic rebuke, but a coordinated attempt to dismantle the conditions that allow expert evidence to metastasize into what many practitioners, myself included, have privately recognized for years as an expert arms race.

 Why the Expert ‘Clown Car’ Keeps Appearing

The Report’s most important insight is implicit rather than rhetorical. The problem is not bad experts, but bad incentives. Under the existing Rules, there is little downside to retaining an additional expert and significant perceived risk in not doing so. Counsel fear being outflanked, second-guessed, or accused of under-preparation. The safest course becomes over-preparation, even when everyone in the room knows the marginal value of the next expert opinion is close to zero.

The Working Group identifies several symptoms of this dynamic, including “the number of experts being engaged,” “expert bias,” and the way expert evidence is presented in a form that “can make it more difficult to understand”.^[2]

Left untouched, these dynamics perpetuate delay, inflate cost, and weaken confidence in adjudicative outcomes. The Report treats expert proliferation not as a trial management issue, but as a design flaw embedded in the litigation process itself.

 From Phase 2 Ambition to Final Restraint

It is worth pausing at this point to understand how the Working Group arrived at the final expert-evidence proposals in Section 6(Q)^[3], because the recommendations in the Final Policy Report are not identical to what was put forward in Phase 2. I blogged about the Phase 2 recommendations in my Substack, “The End of the Duel: Joint Experts in Ontario’s Overhaul”^[4].

That difference is deliberate, and it matters.

In the Phase 2 Consultation Paper, the Working Group advanced a more assertive reform agenda. It proposed expanding the use of joint experts as a primary tool to “reduce the number of experts testifying at trial and to tackle the issue of expert bias,” alongside mandatory expert conferencing and standardized reporting requirements. These proposals were rooted in a clear diagnosis that the existing system allowed expert evidence to proliferate in ways that increased cost, lengthened trials, and undermined clarity. The goal in Phase 2 was to intervene decisively.

The consultation response, however, was mixed, and in some areas, sharply critical. While there was broad support for clarifying expert roles and codifying admissibility standards, “few Consultees supported the compelled use of joint experts,” and many opposed it outright. Concerns were raised that mandatory joint experts could increase delay and expense if parties felt bound by an unfavourable opinion, create incentives for “shadow experts,” or unduly shift decision-making power away from the trial judge. Similar resistance emerged in response to proposed expert conferencing, with consultees warning of increased cost, loss of counsel control, and the risk that a more forceful expert could dominate the process.

The Final Policy Report reflects that feedback, but it does not abandon the reform project. Instead, it recalibrates it. Rather than imposing joint experts across the board, the Working Group adopts a reduced and targeted approach, proposing that joint experts be presumptively required only for defined “financial issues,” including the quantification of economic loss and care costs in personal injury cases, and certain real estate valuations. These are areas where methodology is relatively standardized, disputes are primarily quantitative, and the risk of partisan distortion is at its highest.

For all other issues, the Final Report stops short of compulsion but still requires parties to actively consider the use of a joint expert, with any dispute addressed early through case management. The same pattern appears with expert conferencing. Despite significant opposition, the Working Group ultimately concludes that conferencing remains a “compelling mechanism” to narrow disputes and reinforce the expert’s duty to the Court, but limits the presumption to Trial Track cases, while preserving judicial discretion to dispense with it where inappropriate.

Seen in this light, the Final Report is not a retreat from reform but a refinement of it. The Working Group chooses restraint over rigidity, discretion over blunt force. The core objectives remains intact, namely reducing duplication, curbing expert bias, and restoring proportionality. What changes is the mechanism. Narrower presumptions, clearer guardrails, and greater reliance on early judicial oversight is recommended rather than universal mandates.

That context matters. The expert evidence reforms that follow are not the product of hesitation or compromise for its own sake. They are the result of deliberate course correction, informed by consultation, aimed at producing reforms that are not only principled but workable.

Reasserting Gatekeeping as a Rule, Not a Hope

 

One of the most consequential shifts in the Report is the decision to codify the admissibility requirements for expert evidence drawn from the Supreme Court’s decision in White Burgess Langille Inman v. Abbott and Haliburton Co., 2015 SCC 23^[5]. I discussed the leading case law on the issue of partisan assessments in my blog from earlier this past summer, “The Credibility Crisis: Rebuilding Trust in Expert Evidence Through Civil Reform”^[6]. The proposed rule makes clear that expert evidence is not admissible simply because it exists or because a party paid for it. It must be “necessary to assist the trier of fact” and “sufficiently beneficial to the trial process to warrant its admission despite the potential harm”.

This is a cultural reset. By embedding the gatekeeping function directly into the Rules, the Working Group moves expert admissibility from a discretionary afterthought to a front-end expectation. The message is unmistakable. Expert evidence must earn its place. Courts are encouraged to weigh not just relevance, but proportionality and systemic impact.

Joint Experts as a Brake, Not a Bludgeon

The most visible reform aimed at expert overuse is the Report’s refined approach to joint litigation experts. Importantly, the Working Group backs away from a universal mandate, acknowledging strong negative feedback regarding compelled joint experts. But it does not abandon the concept. Instead, it narrows and targets it.

Joint experts will be presumptively required for defined financial issues, including the quantification of economic loss and care costs in personal injury cases, and certain real estate valuations . These are precisely the areas where dueling experts most often add cost without advancing understanding.

The significance of this move lies less in the categories themselves and more in the signal it sends. Expert evidence in these domains is no longer treated as inherently adversarial. Where methodology is standardized and disputes are primarily quantitative, neutrality is not only possible but preferable.

For all other issues, parties must still actively consider a joint expert, with disputes addressed early at a Directions Conference or One-Year Scheduling Conference. This shifts expert strategy upstream. Instead of commissioning reports in isolation, counsel must justify the need for separate experts in real time, before positions harden and costs are sunk.

Expert Conferencing: Forcing Opinions to Confront Each Other

Perhaps the most pointed response to expert bias is the Report’s endorsement of presumptive expert conferencing in Trial Track cases. Despite strong opposition during consultation, the Working Group concludes that conferencing “provides a compelling mechanism to narrow and clarify the key differences between expert opinions” and reinforces that an expert’s primary duty is to the Court.

This is not a cosmetic change. By requiring experts to meet, confer, and produce a joint report identifying areas of agreement and disagreement, the Rules expose artificial disagreement. Trial testimony is then focused largely on the remaining points of divergence. Posturing becomes harder when experts must explain their differences face to face.

The Working Group acknowledges that conferencing will not be appropriate in every case and preserves judicial discretion. But the presumption itself is powerful. It reorients expert evidence away from advocacy and toward explanation.

Re-Sequencing Evidence to Strip Away Illusions

The Report also proposes re-sequencing expert evidence at trial, requiring fact witnesses to testify first, followed by expert evidence presented issue by issue. I think this change matters more than it appears to at first glance.

Expert disagreement often looks deeper than it is because it floats free of a settled factual record. By anchoring expert opinion in established facts, the trier of fact can more easily see whether divergence reflects genuine methodological disagreement or selective factual emphasis. As the Report notes, this sequencing makes it “more apparent where the experts disagree and why”.

Why This Matters in the Real World

These reforms are not academic. They strike at the heart of personal injury, insurance, and institutional litigation, precisely the areas where expert costs can eclipse damages and delay can become a litigation strategy. In those cases, expert evidence often drives settlement leverage rather than adjudicative truth.

By constraining how expert evidence is deployed, the Report seeks to rebalance that equation. Earlier clarity promotes earlier resolution. Fewer experts reduce sunk costs. Narrower disputes make mediation more meaningful. In short, the reforms aim to restore expert evidence to its proper role, that of assisting the Court, not overwhelming it.

Demise of the Expert Clown Car

The Final Policy Report does not promise a world without disagreement. Nor does it claim that expert evidence can ever be simple. From my mediator’s seat, what it rejects is the assumption that more experts produce better justice.

By tightening admissibility, targeting joint experts, mandating expert conferencing in appropriate cases, and restructuring how expert evidence is presented, the Working Group takes direct aim at a long-standing pathology of civil litigation. The days of the expert clown car, where opinions pile in until they collapse under their own weight, are no longer treated as an unfortunate inevitability.

If these reforms are implemented, expert evidence in Ontario will still matter. But it will matter for the right reasons.