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Medical Negligence, Misnomer, and Discoverability

By Erin Crochetiere

The action in Spry v. Southlake Regional Health Centre et al., 2022 ONSC 1783 involved a claim for medical negligence following the plaintiff’s attendance at the emergency room at Southlake Regional Health Centre (“Southlake”) on February 16, 2018. The plaintiff commenced an action against Southlake, Peter Ko, a physician’s assistant, and Dr. Ian Mak, the attending emergency room physician.

The statement of defence delivered by Dr. Mak, delivered in February 2020, indicated that at some point on the date of loss, the plaintiff’s care had been transferred to “another emergency room physician.”

Examinations for discovery took place in September of 2020. During the examination for discovery of Dr. Mak, Dr. Mak identified the signature on one of the emergency room progress notes as the signature of Dr. James Shin.

The plaintiff brought a motion to add Dr. Shin to the action pursuant to the Doctrine of Misnomer and/or the Doctrine of Discoverability.


The motion judge considered the applicability of the doctrine of misnomer, and noted to the applicable legal principles as outlined in St. Loy-English v. The Ottawa Hospital et al., 2019 ONSC 6075:

As with most discretionary remedies, results are fact driven and case specific. Despite, this, a number of principles may be derived from the jurisprudence. It is useful to summarize these as follows:

(a)  When a plaintiff does not know precisely who to name as defendants it is permissible to name unidentified defendants by way of a pseudonym. It would be better to bring transparency to this practice by naming them as “certain unidentified physicians collectively referred to as Dr. Doe” but the use of “Dr. Doe” or “Dr. X” is a practice that the courts have accepted as appropriate shorthand.

(b)  It is not necessary to name multiple Dr. Doe’s and to precisely guess how many defendants to implicate. Providing the claim is drafted in a manner to identify what allegations are made against individuals filling specific roles, the “litigation finger is divisible” and may point at more than one unknown defendant.

(c)  Unlike a claim relying on discoverability to postpone the running of the limitation period, use of a pseudonym and subsequent correction of a misnomer is not subject to a due diligence requirement and will not be defeated by mere delay.

(d)  Use of a pseudonym does not give carte blanche to get around the limitation period. Although the Act does not narrow the common law understanding of misnomer and preserves the power of the court to correct it, it does prohibit addition of parties if the limitation period has expired. The distinction is critical. It is the difference between correcting the claim to properly name a party already included in the action and adding a new party.

(e)   To be a misnomer, the plaintiff must clearly have intended to sue the proposed defendant. The pleading must be drafted with sufficient particularity that an objective and generous reading of the pleading would demonstrate that the “litigation finger” is pointing at the proposed defendant. To put this another way, the pleading must be sufficiently clear that a properly informed defendant reading the allegation would be able to recognize that he or she was the target of the allegation. The allegation must be clear and definite on its face and not held together through a series of assumptions about what the person reading the statement of claim might know.

(f)   Notice to the defendant within the limitation period cannot be a factor in deciding whether or not misnomer applies for the simple reason that, as discussed earlier, there is no requirement to serve a defendant within the limitation period. The question is not whether the defendant did know he or she was being sued but whether on a fair reading of the claim he or she would have known.

(g)  Notice is relevant to the question of prejudice and the exercise of discretion. Actual notice to the proposed defendant will generally obviate any injustice in subsequently correcting the misnomer. Delay is also relevant to the issue of prejudice and to the exercise of discretion.

(h)  Notice may be sufficient if the claim against an unknown party has been brought to the attention of the named defendant and to an employer, organization or insurer with the means to determine who was involved in the alleged acts or omissions. In that case it may not be unfair to correct the misnomer once the identity of the other defendant is known even in the absence of actual notice.

(i)   It is not useful for misnomer motions to be decided based on technicalities or vagaries of pleading. The object of pleading analysis should not be one of looking for traps, tricks or loopholes. We should not be engaged in the legal equivalent of “whack a mole” or “gotcha”. Rather, the question in every case should be whether it is reasonable and just to allow the pleading amendment and whether it is permitted by the governing legislation.

The motion judge was of the view that the facts of the case were unusual, as two experienced medical negligence lawyers, as well as the plaintiff’s experience medical expert, reviewed the records and determined that Dr. Mak was the responsible physician. Further, the hospital and Mr. Ko, based on their pleadings, made a similar mistake.

The Court held that if this was an error, and Dr. Shin was in fact a responsible physician, then Dr. Shin would suffer no non-compensable prejudice if he was to be added as defendant at this stage. He further found that the failure to identify Dr. Shin at an earlier stage was unintentional and understandable in the circumstances.

Finally, the motion judge found that Dr. Shin, upon reading the claim, would have known that the intended target of the claim were the doctors who treated the plaintiff in the emergency room, which would include him.


The judge went on to consider whether, based on the doctrine of discoverability, the plaintiff would be permitted to commence a claim against Dr. Shin pursuant to Section 5 of the Limitations Act, 2002, S.O., c.24, Sch. B.

The motions judge noted the recent Supreme Court of Canada decision in Grant Thornton LLP v. New Brunswick, 2021 SCC 31, which held that:

“A claim is discovered when the plaintiff has knowledge, actual or constructive, of the material facts upon which a plausible inference of liability on the defendant’s part can be drawn” at para. 42.

Grant Thornton further held that, the degree of knowledge must be more than “mere suspicion or speculation” at para 46.

The judge further noted that, in medical malpractice cases, it is not easy to identify the negligent actor and that the material facts that the plaintiff must be aware of include who was responsible for the alleged damage.

The Judge held that, given that the records were not clear, and a number of people incorrectly assumed that Dr. Mak was the only doctor in charge of the plaintiff’s care from review of the records, there was no carelessness on the part of the plaintiff, or her lawyers, in the investigation of the claim. Accordingly, the plaintiff’s claim against Dr. Shin was discovered when Dr. Mak delivered his statement of defence which indicated that another doctor had assumed the care of the plaintiff on the night in question. 


The key takeaway for this decision is that, particularly in medical negligence cases where a claim outlines the date and particulars of a medical event, a plaintiff may be successful in bringing a defendant into the action after the expiry of the applicable limitation period, by application of the misnomer doctrine.

The decision further suggests that the legibility of medical records may be a significant factor in considering whether the plaintiff could have discovered the claim upon review of them. Interestingly, the decision does not make any reference to the fact that the plaintiff presumably would have interacted with Dr. Shin directly during her care. If she did, she arguably should have discovered the claim against him at an earlier date.