Evidence - Expert Opinion - Expert Report (2). Agrest v. Pekker
In Agrest v. Pekker (Ont CA, 2023) the Court of Appeal held that unsworn reports of a "purported expert witness" were inadmissible:
 Further, we see no error by the application judge in excluding the report or statement of Professor Solomon, a purported expert witness on Russian law and governance. We agree with the application judge’s reasons for excluding this evidence. The report was not supported by an affidavit sworn by Professor Solomon and was inadmissible. Furthermore, we agree that even if the report was properly before the application judge, it was within the discretion of the application judge to determine the weight to apportion to the purported evidence. In this case, he chose not to assign any weight to the statement as it was not sworn, nor did it affirm that the specific Russian proceedings, which were the subject of the application, were tainted by fraud.. Wilkin v. Health Services Appeal and Review Board
In Wilkin v. Health Services Appeal and Review Board (Div Court, 2023) the Divisional Court considered (and dismissed) a JR against a ruling of the HPARB brought by a doctor who objected to OHIP's calculation of his billing submitted under the Schedule of Benefits for Physician Services, R.R.O. 1990, Reg. 552/92 (“Schedule of Benefits”). The specific issues were OHIP's use of expert evidence on the interpretation and application of the billing codes.
In these quotes the court characterizes the role of the participant-expert:
 Dr. Davidson, on behalf of OHIP, testified as to how OHIP claims are assessed, the interpretation, application, and amendments to the Schedule of Benefits, and described the Ministry of Health’s rationale for disallowing the disputed fee codes in this case.. Wasylyk v. Simcoe (County)
 The Applicant objected to Dr. Davidson giving opinion evidence on whether the claims in this case had been properly assessed. The Board ruled that it should hear the evidence because it would be relevant and helpful. The Board Chair noted that much of the evidence as described did not sound like opinion evidence, but that counsel could object to any opinion evidence. The Chair also observed that the Board was aware that Dr. Davidson was not a lawyer, and that questions of statutory interpretation would be for the Board to determine. Counsel for the Applicant chose not to object during the examination-in-chief of Dr. Davidson. Counsel cross-examined Dr. Davidson and raised a challenge to aspects of that evidence in her final submissions.
Did the Board Unreasonably Admit the Evidence of Dr. Davidson?
 The Applicant acknowledges that Dr. Davidson gave fact evidence that was admissible as to context, the process of claims analysis and settlement, and the decision denying some of the Applicant’s claims for payment under the Schedule of Benefits.
 However, counsel for the Applicant submits that this fact evidence was interwoven with impermissible opinion evidence from an expert who, although qualified, was not an unbiased, neutral expert. The Applicant emphasized that Dr. Davidson was employed by the Ministry, was identified as the “client” during the hearing and was involved in an informal review of the fees claimed prior to the hearing before the Board.
 To summarize the findings on this question, I find that the Board reasonably received Dr. Davidson’s evidence, as an employee for one of the parties with expertise in the areas of orthopedic surgery and the application of OHIP billing codes to surgical procedures. Further, as the overview of Dr. Davidson’s evidence below shows, much of the evidence she gave was explanatory of OHIP’s process and decision. The Board accurately described this as fact evidence.
 The Board applied its own judgment to the central question in dispute: the application of the fee codes to the surgical procedures undertaken by the Applicant. Ultimately, the Board preferred OHIP’s interpretations of the disputed fee codes to those of the Applicant. Although he does not challenge the fact that this was a reasonable and available interpretation that was open to the Board, the Applicant submits that the error in permitting Dr. Davidson to testify meant that the application should be allowed, and a new hearing ordered before the Board.
 Specifically, the Applicant submits that the Board erred or acted unreasonably in describing Dr. Davidson as a “participant expert” as that term has been applied under r. 53.03 of the Rules of Civil Procedure, R.R.O. 1990, Reg. 194 in civil proceedings and as described in the decision of the Court of Appeal in Westerhof v. Gee Estate, 2015 ONCA 206, 124 O.R. (3d) 721. Although the “participant expert” classification is not apt in the case of Dr. Davidson, this does not make her evidence inadmissible. The Board has wide latitude to admit evidence it finds to be relevant and useful. Further, Dr. Davidson’s evidence was akin to a type of expert evidence which is recognized in the civil context that applies to employees of a party.
Participant Experts in Civil Proceedings
 Westerhof recognizes that a broader group of witnesses with expertise may testify in civil claims even though this group would not meet the usual criteria for independent experts retained by a party. This broader group includes “participant experts” who may have been involved in the events underlying the litigation and have relevant expertise and information relative to the issues in dispute: for example, physicians who treat injuries that are relevant to personal injury cases. It also includes “non-party experts” such as statutory accident benefits insurers who form opinions for reasons separate from the litigation.
 In both such examples, participant and non-party experts are “not engaged by a party to form their opinions, and they do not form their opinions for the purpose of the litigation”: Westerhof, at para. 82. They are not litigation experts. In civil trials, counsel is not required to follow the provisions of r. 53 prior to tendering evidence from these witnesses such as having the witness prepare an expert report and sign an acknowledgement of the expert’s duty to provide fair, neutral and non-partisan opinion evidence within the scope of their expertise.
The Admission of Expert Evidence before the Board
 Section 23(4) of the Health Insurance Act, R.S.O. 1990, c. H.6 grants the Board the powers found in section 15 of the Statutory Powers Procedure Act (“SPPA”). That provision provides that:
15 (1) …a tribunal may admit as evidence at a hearing, whether or not given or proven under oath or affirmation or admissible as evidence in a court,The Divisional Court has recognized that this section gives tribunals “wide powers concerning the admission of evidence, including experts”: Connor Homes v. Director, 2021 ONSC 3195 (Div. Ct.), at para. 47; Ontario Racing Commission v. Hudon, 2008 CanLII 68156 (Div. Ct.), at para. 23. In M.R. v D.E., 2016 ONSC 1542, the Divisional Court noted at paragraph 21 that in tribunal proceedings governed by the SPPA, while the principles in R. v. Mohan, 1994 CanLII 80 (SCC),  2 S.C.R. 9 remain relevant to the admission of expert evidence, statutory tribunals are not bound by those principles.
(a) any oral testimony; and
(b) any document or other thing, relevant to the subject-matter of the proceeding and may act on such evidence...
Overview of the Evidence of Dr. Davidson
 Dr. Davidson testified first about her background and expertise, the nature of her role with OHIP, the claim and adjudication process within OHIP, and communications issued from OHIP to physicians to assist with billing. This can fairly be described as general fact and context evidence. It is not the subject of controversy.
 Dr. Davidson testified about the steps she took relative to Dr. Wilkin’s claims for treatment. She became involved after the OHIP assessment when Dr. Wilkin sought review by the Board. At that stage, she reviewed the material and provided a third level of review of the disputed codes OHIP payment decisions and denials. Counsel for the Applicant objected on the basis that Dr. Davidson’s opinion on the point was not admissible. Counsel’s objection was grounded in the submission that Dr. Davidson was not a “participant” expert. Counsel also raised fairness concerns because Dr. Davidson’s role in “adjudicating” the claim had not been disclosed until this stage.
 Dr. Davidson’s evidence was relevant and admissible evidence that fell within the discretion of the Board to hear. This flows from s. 15 of the SPPA as well as prior decisions of this court, as discussed above, which recognize that statutory tribunals have discretion including in choosing to admit opinion evidence.
 Further, although Dr. Davidson may not have been properly analogous to a “participant expert” as that label has been applied to certain types of witnesses in civil proceedings, this does not mean that evidence from someone in her role, and with her knowledge, would not be admissible on other alternative bases had this been a civil proceeding.
 Dr. Davidson was clearly not an independent expert retained to give an opinion in litigation, and the type of expert in civil proceedings to whom r. 53 applies. Nor does her role fit the criteria of a “participant expert”. The defining characteristics of a “participant expert” from Westerhof is a witness with expertise who is involved prior to the litigation and for a purpose unrelated to the litigation but related to the factual events underlying the litigation.
 However, Dr. Davidson did meet the criteria for a third type of witness, that being as a litigant’s employee with expertise.
 This category of witness was recognized in Kon Construction v. Terranova Developments Ltd., 2015 ABCA 249, 602 A.R. 327 as a potential source of opinion evidence. At paragraph 35, the Court of Appeal for Alberta described three categories of “experts”:
(a) independent experts who are retained to provide opinions about issues in the litigation, but were not otherwise involved in the underlying events. This is the category of expert witness contemplated by White Burgess and Mohan. I conclude that the Board did not act unreasonably in admitting Dr. Davidson’s evidence. The reasons reveal that the Board came to its own conclusions, having heard the Applicant’s rationale, followed by OHIP’s decision as described by Dr. Davidson. Dr. Wilkin testified about his rationale for the applicable codes to the medical procedures he performed. Although the Board described Dr. Davidson as a participant expert, in ruling on the objection, the Board directed itself not to treat Dr. Davidson as a legal expert. It instead treated her as a witness with expertise as to the processing of claims and with knowledge of the orthopedic procedures and terms used in this case.
(b) witnesses with expertise who were involved in the events underlying the litigation, but are not themselves litigants. An example is the family physician in a personal injury case who is called upon to testify about his or her observations of the plaintiff, and the treatment provided; and
(c) litigants (including the officers and employees of corporate litigants) who have expertise, and who were actually involved in the events underlying the litigation.
 I would also not give effect to the submission that opinion evidence was intertwined with the fact evidence because the summary of evidence shows that most of Dr. Davidson’s evidence was descriptive and factual. The final question was most clearly a question of opinion. The Board reasonably admitted it, having acknowledged the constraints on her evidence and the separation of its role from that of Dr. Davidson.
In Wasylyk v. Simcoe (County) (Ont CA, 2023) the Court of Appeal considered an appeal record issue where the expert report was adopted by the expert, not entered as an exhibit but still considered by the court (as an 'aide-memoire'):
 During Mr. Leggett’s testimony at trial, he was asked to read into the record and adopt conclusions in the reports, which he did. Copies of the reports were given to the trial judge, at her request, when this occurred.. Ontario (Attorney General) v. Trinity Bible Chapel
 The reports were not, however, marked as numbered or lettered exhibits. The parties agreed then, and agree now, that the reports were only provided to the trial judge as aides memoire and were not themselves evidence. As this court stated in Moore v. Getahun, 2015 ONCA 55, 124 O.R. (3d) 321, at para. 86, leave to appeal refused,  S.C.C.A. No. 119: “If an expert's report has not been entered into evidence as an exhibit, it has no evidentiary value, even if provided to the trial judge as an aide memoire.” Only Mr. Leggett’s oral testimony (including what he read into the record from the reports) constituted his evidence.
In Ontario (Attorney General) v. Trinity Bible Chapel (Ont CA, 2023) the Court of Appeal considered a church group's appeal against a dismissal of their Charter s.52 declaration application involving the COVID provisions of the Reopening Ontario (A Flexible Response to COVID-19) Act, 2020.
These quotes consider the difference between a litigation versus a participation expert witness:
1) The motion judge did not err in her treatment of the expert evidence. St. Marthe v. O’Connor
 The appellants argue that the motion judge erred by admitting and heavily relying on the opinion evidence of Dr. McKeown, particularly in support of her findings that there was any risk of COVID-19 transmission outdoors and that Ontario’s gathering restrictions reduced infection rates. They submit that he was a fact witness, not a properly qualified expert witness, and for this reason did not complete the Acknowledgement of Expert’s Duty form under r. 53.03 of the Rules of Civil Procedure, R.R.O. 1990, Reg. 194 The appellants contend that his opinion evidence was not necessary to assist the trier of fact.
 The respondent highlights that the appellants did not object to the admissibility of Dr. McKeown’s evidence in the court below. In fact, they attempted to rely on his evidence to support their s. 1 argument. Therefore, no substantial wrong or miscarriage of justice occurred.
 In any event, the respondent asserts that Dr. McKeown was a participant expert who was not required to comply with r. 53.03 and whose evidence was admissible for the truth of its contents, relying on Westerhof v. Gee Estate, 2015 ONCA 206, 124 O.R. (3d) 721, leave to appeal refused,  S.C.C.A. No. 198, at para. 60. He was a witness with “special skill, knowledge, training or experience”; he directly participated in reviewing and assessing information related to COVID-19 as part of his role as Associate Chief Medical Officer of Health; and he formed his opinions as part of the ordinary exercise of his knowledge, training, and experience while advising the Ontario government on its pandemic response.
 I agree.
In St. Marthe v. O’Connor (Ont CA, 2021) the Court of Appeal considered expert reports, and particularly those of 'non-party experts' as opposed to 'litigation experts':
The Law of Expert Testimony
Expert Opinions Generally
 In civil proceedings, experts retained by a party to testify in a proceeding must prepare an expert report to be shared with all parties prior to trial. This is provided for in r. 53.03 of the Rules of Civil Procedure, R.R.O. 1990, Reg. 194. These experts are referred to as “litigation experts”: Westerhof v. Gee Estate, 2015 ONCA 206, 124 O.R. (3d) 721, at para. 6, leave to appeal refused, 36445 (October 29, 2015) and 36451 (October 29, 2015).
 The expert report includes an outline of the litigation expert’s opinion and anticipated testimony. This sets limits on the expert testimony that may be given and ensures that all parties have proper notice of the roadmap for the opinion evidence to be provided: Bruff-Murphy v. Gunawardena, 2017 ONCA 502, 138 O.R. (3d) 584, at para. 62, leave to appeal refused,  S.C.C.A. No. 343. The report also includes an acknowledgment of the expert’s duty: Imeson v. Maryvale (Maryvale Adolescent and Family Services), 2018 ONCA 888, 143 O.R. (3d) 241, at para. 60, leave to appeal refused,  S.C.C.A. No. 35.
 Litigation experts are distinguished from non-party experts. In Westerhof, at paras. 60-62, this court defined a participant or non-party expert as “a witness with special skill, knowledge, training, or experience who has not been engaged by or on behalf of a party to the litigation”. Non-party experts are subject to different rules than litigation experts.
Non-Party Expert Evidence
 Non-party medical experts such as Dr. Mussett who have special skill, knowledge, training, or experience, may give opinion evidence for the truth of its contents provided the opinion is given as part of the exercise of their skill and knowledge while observing or participating in the events at issue, the opinion is not a “complex vocational opinion requiring highly specialized expertise”, and it was disclosed to the opposing party: Westerhof, at paras. 60-62, 165.
 Non-party expert opinions are usually contained in clinical notes and records, or reports prepared for the purpose of consultation and treatment: Imeson, at paras. 61-63.
 A non-party expert need not provide a r. 53.03 expert report, where the opinion is based on the witness’s observation of or participation in the events at issue and the opinion was formed as part of the exercise of skill, knowledge, training, and experience while observing or participating in the events: Westerhof, at para. 60.
 One reason the requirement to provide a r. 53.03 expert report does not generally apply to non-party experts, is that disclosure problems do not exist in relation to the opinions of non-party experts requiring that they comply with r. 53.03. Non-party experts typically prepare documents summarizing their opinions contemporaneously with their involvement in the events. These summaries, or the expert’s notes and records, can be obtained through the discovery process: Westerhof at para. 85.
 Where the opinion evidence extends beyond the witness’s observation of or participation in the events and the opinion was not formed while observing the events, the expert must comply with the requirements in r. 53.03 with respect to the portion of the opinion that exceeds these limits: Westerhof, at para. 63. Rule 53.03 provides that experts must include the instructions given, a summary of the opinion, and the reasons for the opinion, among other requirements.
 Problems arise where disclosure of an opinion of a non-party expert is given only on the eve of or during the trial: Westerhof, at para. 90.
 It is not an error for a trial judge to prevent a non-party expert from giving opinion evidence that goes beyond the expert’s observations and comments in the original report if the opinion was not disclosed well in advance of trial: Hoang v. Vicentini, 2016 ONCA 723, 352 O.A.C. 358, at para. 30.
The Judge’s Role in the Admission of Evidence
 In White Burgess, the Supreme Court established a two-part framework for admitting expert evidence. First, the court must assess whether the opinion evidence meets the threshold requirements of admissibility: relevance, necessity, absence of an exclusionary rule, and has been provided by a properly qualified expert: White Burgess, at para. 23; see also R. v. Mohan, 1994 CanLII 80 (SCC),  2 S.C.R. 9, at pp. 20-25. If it does, the court engages in a discretionary analysis to determine if its probative value outweighs its prejudicial effect: White Burgess, at para. 24.
 As part of its gatekeeper function, the court may exclude evidence from a non-party expert if it does not meet the test for admissibility: Westerhof, at para. 64; Imeson, at para. 83.