Expert Qualification and Reliability of the Expert Opinion are Separate Legal Issues: Nova Scotia (C
The Nova Scotia Court of Appeal decision in Nova Scotia (Minister of Community Services) v. J.M, 2018 NSCA 71 contributes to the jurisprudence regarding the qualification of an expert witness by clarifying that the qualification of the expert, and the reliability of the expert’s testimony, are separate legal questions. Considering both matters together is an error in law, because it fails to consider whether the expert has the proper credentials to give an expert opinion, and fails to consider whether that opinion is more probative than prejudicial. Bryson J. demonstrates the correct assessment of expert qualification and reliability of the expert evidence in NS (Minister of Community Services).
Admissibility of expert evidence
The admissibility of expert evidence is assessed by applying the two-stage framework formulated in R v Abbey (No2). The first stage of the analysis is a rule-based approach derived from R v Mohan, which determines whether the expert evidence meets the threshold of admissibility. The trial judge considers whether the evidence is logically relevant, necessary to assist the trier of fact, subject to any exclusionary rules, and whether or not the expert is properly qualified. To be properly qualified, an expert must be impartial, independent, and unbiased.1 The second stage of the analysis is an exercise of the trial judge’s gatekeeper role. The judge has the residual discretion to exclude expert evidence, where the cost of admitting the evidence outweighs its benefit to the court. Legal relevance, necessity, reliability, and the absence of bias are considerations when weighing the costs and benefits of admitting the evidence.2
NS (Minister of Community Services) is an appeal to an order excluding expert testimony in a child protection proceeding. R.R. was denied unsupervised access to his daughter after samples of his urine tested positive for cocaine, and challenged the reliability of the urine tests. The issue at trial was whether Doctor Nassar, director of the QE II lab that conducted the urine tests, is qualified to provide expert opinion evidence in the field of forensic and analytical toxicology.3
In assessing whether he was qualified to provide expert opinion, Forgeron J. held that Nassar’s qualifications and the reliability of the lab test results were intertwined, and must be assessed in conjunction.4 If the lab tests were not reliable, Nassar was not properly qualified. Where the lab was not forensically accredited, or subject to external oversight, Forgeron J. held that the test results were unreliable and, therefore, Nassar was not a properly qualified expert.
On appeal, Bryson J. reversed the decision, holding that merging Nassar's qualifications with the analysis of the labs reliability was an error in law.5 For the purpose of determining expert qualification, the reliability of the test results are clearly distinct.6 The decision misapplied the law by failing to consider the credentials of the expert, or weigh the costs and benefits of admitting the evidence.
The proper application of the Abbey framework to the facts of the case was demonstrated in the appeal decision. At the threshold stage of the Abbey framework, proper qualification of the expert witness assesses whether the proposed expert has special skills, knowledge, or experience necessary to assist the trier of fact. Expert evidence is admissible where the trier of fact needs assistance drawing an inference because the evidence presented is likely to be outside their knowledge or experience.7 Subsequent jurisprudence in White Burgess has established that witness impartiality is a factor in the threshold qualification of an expert. Where an expert accepts their duty to impartiality, the duty shifts to the other party to demonstrate the expert is unwilling or unable to comply with the duty.8 Bryson J. noted in his analysis that Nassar’s credentials were impressive, and demonstrated expert knowledge in the field of forensic and analytical toxicology. The proper application of the Abbey framework would have determined Nassar was qualified to give the opinion, no evidence demonstrated he was unwilling to adhere to his recognized duty of impartiality, and the evidence was necessary to assist the trier of fact.9
At the gatekeeper stage of the Abbey analysis, the probative value of the evidence in terms of relevance, reliability, and necessity is weighed against the cost it would have to trial fairness in terms of time consumption, confusion, and prejudicial effects.19 The trial judge was obliged to weigh the costs and benefits of admitting the evidence, but no such analysis occurred.10 Concerns related to the reliability of the evidence, such as the labs lack of forensic accreditation, and Nassar’s role as director, are appropriately addressed at the gatekeeping stage. As clarified by Bryson J., the correct assessment under the Abbey framework requires the risk of admitting the problematic evidence to be weighed against its benefit to the court. The omission by Forgeron J. to consider the probative value of the evidence in her decision was significant, since the appeal decision concluded that a cost-benefit analysis of Nassar’s testimony favored admission.11
The case makes an important contribution to the relevant jurisprudence by establishing a clear rule against treating the qualification of the expert, and the reliability of the expert testimony, as a single legal matter. Practically, this case could serve as precedent for how to conduct an Abbey analysis where there are concerns surrounding the reliability of the tendered expert evidence. The principal to be applied is that the trial judge cannot determine the expert is unqualified due to their testimony being unreliable. The Abbey framework must be utilized to assess whether the expert meets the threshold qualification test, and, whether reliability concerns make the evidence more prejudicial than probative at the gatekeeper stage. Generally, the case is valuable to the law surrounding qualification of an expert as it illustrates the proper way to apply the Abbey framework to a set of facts. The decision further highlights the necessity of the Abbey framework, by demonstrating that where the Abbey framework was misapplied, an otherwise qualified expert with probative evidence to offer the court was excluded.
In conclusion, the decision in NS (Minister of Community Services) contributes to the jurisprudence surrounding admissibility of expert evidence by establishing expert qualification, and the reliability of the proposed evidence, are separate legal questions. When the reliability of the evidence is determinative of whether or not a proposed expert is qualified, the expert’s credentials are not assessed, and no cost-benefit analysis occurs. This is an error of law in applying the Abbey framework because it fails to consider whether the expert has the requisite expertise to assist the trier of fact in drawing an inference, or whether admitting the opinion is more probative than prejudicial. The analysis of Bryson J. in the decision clarifies the proper analysis of reliability concerns under the Abbey framework.
1 Sidney N Lederman, Alan W. Bryant & Michelle K. Fuerst, “The Law of Evidence in Canada”, 5th ed. (Toronto: LexisNexis Canada, 2018) 839 at para 54
2 R v Abbey (No 2), 2017 ONCA 640, at para 48 [Abbey]
3 Nova Scotia (Minister of Community Services) v. J.M., 2018 NSSC 31, at para 3
4 Nova Scotia (Minister of Community Services) v. J.M., 2018 NSSC 31, at para 24
5 Nova Scotia (Minister of Community Services) v. J.M., 2018 NSCA 71, at para 21 [NS Minister of Community Services]
6 Nova Scotia (Minister of Community Services) v. J.M., 2018 NSCA 71, at para 18 [NS Minister of Community Services]
7 Sidney N Lederman, Alan W. Bryant & Michelle K. Fuerst, “The Law of Evidence in Canada”, 5th ed. (Toronto: LexisNexis Canada, 2018) 852 at para 87
8 Sidney N Lederman, Alan W. Bryant & Michelle K. Fuerst, “The Law of Evidence in Canada”, 5th ed. (Toronto: LexisNexis Canada, 2018) 858 at para 102
9 Nova Scotia (Minister of Community Services) v. J.M., 2018 NSCA 71, at para 43 [NS Minister of Community Services]
10 Nova Scotia (Minister of Community Services) v. J.M., 2018 NSCA 71, at para 47 [NS Minister of Community Services]
11 Nova Scotia (Minister of Community Services) v. J.M., 2018 NSCA 71, at para 55 [NS Minister of Community Services]
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