Medical Experts and Their Duty to the Court

A doctor shows the scales of justice on the tablet demonstrating the concept of medical experts and their duty to the court

A Cautionary Tale For the Role of Expert Evidence at Trial

In an important medical malpractice trial in 2022, a Judge of the Ontario Superior Court has found two doctors liable for the amputation of the plaintiff’s leg after complications from a fall. In deciding for the plaintiffs, Madam Justice Vermette largely rejected the testimony of two experts who testified for the defendant doctors. Successful plaintiffs’ counsel were lawyers Ryan Breedon of Breedon Litigation, and David Lackman and Jessica Golosky of Gluckstein Lawyers.

Regarding the evidence of defence emergency medicine expert Dr. B, the trial judge found that his testimony amounted to splitting hairs, he gave inconsistent answers, and the judge was astonished by his testimony. Notably, the trial judge adopted the argument made by plaintiffs’ counsel that Dr. B refused “to make obvious concessions” and had “taken on the role of advocate”.

The defence Orthopaedic expert was Dr. P. The trial judge found his “performance as an expert witness deplorable”. Dr. P’s evidence was contradicted by some of the very literature he quoted in his own written reports. His testimony was non-responsive to simple questions, he refused to admit obvious statements and gave answers that made no sense in light of the opinions he provided in his own reports.

This important case, Fortune-Ozoike v. Wal-Mart Canada Corp., 2023 ONSC 421, should be seen as a cautionary tale for medical experts who fail to understand and respect their role in the fair administration of justice. Further, lawyers acting for parties on both sides of medical malpractice cases need to be reminded of the proper role that experts play in the trial process.

In medical malpractice cases, as in all cases, experts hired for the purposes of litigation occupy a special place. These litigation experts have no personal knowledge of the matters at issue between the parties. Ordinarily, without personal knowledge, a witness is simply not permitted to testify. An exception, however, is made when the case involves technical or scientific issues beyond the ordinary understanding of the trier of fact (judge or jury). In these complex cases, the trier of fact may need some “help” to sufficiently understand the complicated issues in order to render a fair verdict. Therefore, experts are allowed to testify and offer opinion evidence, where it would otherwise be excluded, provided they do so in a way that helps the trier of fact.

This helping function means that experts hired for litigation must honour their obligation to help. That is, they must offer testimony that conforms with their duty to assist the Court. Where the expert’s evidence aims to favour the economic interests of one party rather than reliably inform the trier of fact on technical matters, it cannot be said that the testimony conforms with the duty to help. It follows that the testimony they give must be impartial and objective, not favouring the economic interests of one party or the other. Both Dr. B and Dr. P, according to the trial judge in Fortune-Ozoike, failed to fulfil their respective duties to the court to help the judge as the trier of fact. As a result, the trial judge rejected their testimony on key points.

In contrast, the trial judge accepted the testimony of the plaintiffs’ Emergency Medicine expert, Dr. Arun Sayal, and Orthopaedic expert, Dr. David Pichora, in almost all respects material to the outcome. The trial judge found Dr. Sayal to be a “very credible witness”. As for Dr. Pichora, the trial judge found him to be fair, objective and non-partisan. The contrast between the credible plaintiffs’ experts and the incredible defence experts could not be more stark.

An accident and preventable medical errors

On Boxing Day 2013, the plaintiff Jameela Fortune-Ozoike went shopping at a Walmart store where she slipped on a hanger and fell.

Experiencing excruciating pain in her leg, she was transported to the hospital where she was given pain medication as she waited to see a doctor. Based on the emergency room intake assessment, but without any examination or assessment, the emergency room doctor, the defendant Dr. Lian, assumed the patient had suffered a fracture. This assumption was based on incomplete clinical information. In fact, Fortune-Ozoike had suffered a knee dislocation and vascular injury, which exposed her to an increased risk for a serious condition called compartment syndrome. The risk of compartment syndrome is that it can reduce or cut-off the blood supply to the leg and lead to amputation if not diagnosed and treated in a timely way.

Given the serious risks associated with a knee dislocation and the possible development of compartment syndrome, it was essential that a thorough neurological examination take place and that examination be repeated so that any clinical changes suggesting deterioration can be responded to quickly. The ER doctor did contact his orthopedic colleague, the defendant Dr. Lai. The evidence was that Dr. Lian had not carried out the thorough neurological examination required and that Dr. Lai did not take the necessary steps to ensure that the neurologic examination was properly done. These failures would ultimately lead to the amputation of the patient’s leg. By the time the ominous neurological changes were detected, it was too late to save the limb.

The plaintiffs alleged that Dr. Lian and Dr. Lai each breached two applicable standards of care and that these breaches caused Ms. Fortune-Ozoike’s injuries.

The plaintiffs alleged that Dr. Lian failed to assess Ms. Fortune-Ozoike upon being notified by the triage nurse of the patient’s unusual degree of pain. Further, it was alleged that Dr. Lian failed to conduct a competent neurological examination of the patient, or to notify Dr. Lai of his (Dr. Lian’s) suspicion that the patient might be developing compartment syndrome after he reassessed her.

Evaluation of expert testimony

Regarding the actions of Dr. Lian, the standard of care expert for the plaintiff, Dr. Sayal, testified that Dr. Lian failed to perform a proper examination for compartment syndrome when he was advised of the development of concerning clinical symptoms, and that Dr. Lian breached the standard of care by not notifying Dr. Lai of these concerns. Significantly, the trial judge accepted Dr. Sayal’s evidence “unreservedly”. The evidence of the defence expert on this point, Dr. B, was, as stated above, rejected for inappropriately taking on the role of advocate.

On behalf of the patient, Dr. Pichora’s evidence regarding the orthopaedic care provided by Dr. Lai was that this doctor should have attended the bedside and conducted a thorough neurological examination that included comparing arterial findings in the injured leg to those in the uninjured leg. Alternatively, Dr. Lai was required to ensure that this examination was competently performed. The trial judge accepted Dr. Pichora’s evidence and found that Dr. Lai had breached the standard of care. The defence evidence of Dr. P to the contrary was bluntly rejected by the trial judge.

Finally, the trial judge heard evidence from other experts called by the parties on the issue of causation, concluding that the breaches of the standards of care by both Dr. Lian and Dr. Lai were the “but for” cause leading to the amputation of the plaintiff’s leg as a life-saving measure.

Rejection of the testimony from the Defence “experts” and the Judge’s Role as Gatekeeper

In considering whether Dr. Lai breached the standard of care, Justice Vermette accepted the opinion of the plaintiffs’ orthopaedic expert, Dr. Pichora. He gave evidence that a knee dislocation is a limb-threatening injury and that it was incumbent on an orthopaedic surgeon to ensure that the appropriate neurovascular assessment was done. This required seeing the patient in person, or at the very least ensuring, through focused questioning of the emergency physician, that a complete and proper neurovascular assessment was carried out.

The Defence expert, Dr. P, testified that the standard of care did not require Dr. Lai to attend the Hospital to assess the patient himself, did not require Dr. Lai to ask Dr. Lian about the manner in which he was conducting a neurovascular examination, and did not require him to outline the specific assessment to be conducted when giving his orders. In Dr. P’s opinion, Dr. Lai was entitled to rely on Dr. Lian’s assessment as conveyed to Dr. Lai.

During cross-examination, Dr. P gave non-responsive answers to simple questions, and offered testimony inconsistent with his own reports, with Dr. Lai’s testimony, and with authoritative literature in the field of orthopaedic medicine that he had himself cited. Justice Vermette wrote, “while Dr. P signed a Form 53 – Acknowledgement of Expert’s Duty, he did not provide opinion evidence that was fair, objective and non-partisan. He acted as an advocate.”

Justice Vermette “unreservedly” accepted the opinion of plaintiffs’ emergency room expert, Dr. Arun Sayal, when determining whether Dr. Lian breached the standard of care. She found that Dr. Sayal’s opinion was “rational, as well as consistent with the process of differential diagnosis and the foreseeability of harm and risk posed by compartment syndrome to the patient”.

By contrast, Justice Vermette rejected the evidence of defence emergency medicine expert Dr. B on the basis that he had taken on the role of advocate. Dr. B’s opinion had, in substance, largely supported the opinion of Dr. Sayal that Dr. Lian had breached the standard of care; yet, he went to great lengths to avoid conceding this point. Experts acting impartially Justice Vermette found that the causation experts for both sides, Dr. Andrew Dueck (for the defendants) and Dr. Varun Kapila (for the plaintiffs), to be credible witnesses. These experts were largely in agreement about the timeframe in which diagnosis and treatment of compartment syndrome would have preserved all or at least some of the function of the limb.


Litigation experts must honour their obligation to be helpers to the trier of fact, not advocates for a party’s economic interests. The duty to act fairly, objectively, and impartially does not mean that medical experts are precluded from “advocating” for the opinions expressed in their expert reports. Indeed, it is the reasonable expectation of the parties that the experts will do just that. This means that the opinions expressed in expert reports must be sound. The opinions must find their foundation in reliable medical literature, conform with acceptable teachings, and be consistent with good clinical experience. Further, when these opinions are formulated, they must be done knowing that they will be scrutinized by other qualified experts and, where the case does not settle, they will be scrutinized in cross-examination at trial. The opinions must be sound enough to withstand this scrutiny.

In Fortune-Ozoike, the opinions of Dr. Sayal and Dr. Pichora were firmly rooted in good medicine and authoritative literature. As such, these opinions ultimately withstood the test of their colleagues’ critique and cross-examination at trial. The same cannot be said of the evidence of defence experts Dr. B and Dr. P, the significant deficiencies of which were plainly exposed by the careful cross-examination by plaintiffs’ counsel.


Medical malpractice cases are notoriously challenging to prosecute. In most cases, the challenges faced by the patient in litigation are associated with the inherent complexity of the medicine and science involved. In many cases, the plaintiff is seeking treatment from medical professionals due to an injury or some underlying health problem unrelated to any fault on the part of the medical team. It is necessary to tease out the expected prognosis caused by the underlying condition without the alleged malpractice and compare that to the actual outcome following the alleged malpractice. The former scenario imagines a world where the malpractice did not occur, making causation questions difficult. It is unfair to further complicate the challenges faced by the patient by engaging experts who fail to meet their duties as helpers to the court by becoming advocates for the parties who engage them.

In any profession, reasonable disagreement among experts is to be expected. People can come to different conclusions based on their own interpretation of the same general facts. Legitimate differences of opinion are one thing; however, inappropriately advocating for one’s own, or for a litigant’s, economic interests, is an entirely different matter.

As personal injury lawyers, we must ensure that the role of our experts does not overlap with our role as advocates for our clients. We must take care to ensure that our experts understand and honour their duty to the court and to the administration of justice. Fortune-Ozoike v. Wal-Mart serves as an excellent case study on how expert witnesses can fulfil their responsibilities effectively, or can cross a line that impairs or, as here, completely undermines, their credibility.


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