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Adverse Inference:
Negative Presumptions for Failing to Present Evidence
Last Updated: August 08 2026
Question: What happens in an Ontario civil case if a party doesn’t produce relevant documents or call a witness the court expects them to have?
Answer: In Ontario civil litigation, Melville Legal can help explain how adverse inference works when a party fails to produce relevant documents they were required to produce or should have produced, or fails to testify or call a material witness without a legitimate explanation; the court may draw an unfavourable or negative inference that the missing evidence or testimony would have been harmful or would not support that party’s case, and the decision to draw it is discretionary and case-specific, including whether the evidence or witness was within that party’s exclusive control or was equally available to both sides, and whether the witness had key facts; for practical guidance on what to request, document, and argue, you can call (289) 981-7712.
Understanding the Principle of Adverse Inference as an Evidentiary Rule Arising from Failure to Produce Evidence
An adverse inference may arise where a party fails to testify, or where a party fails to lead evidence that is in control of the evidence, and from such a failure the court may thereby presume that the reason for the absence of the evidence or the absence of testimony is that such would negatively affect the party who fails to provide the testimony or the evidence.
The Law
An adverse inference presumption arises from the expectation that where a litigant is in possession of evidence or control of a witness, the litigant would provide the evidence or present the witness unless the evidence or witness is harmful to the case of the litigant. The legal doctrine was provided within the cases of, among others, Tiwari v. Chevalier, 2022 ONSC 3071, and Lane v. Kock, 2015 ONSC 1972, which respectively stated:
[28] Adverse inferences may be drawn from a party’s failure to produce relevant documents they were required to produce or should have produced. (Sarzynick v. Skwarchuk, 2021 BCSC 443, at para. 190.)
[3] The effect of the failure of a party to testify or to call a material witness or other evidence, is summarized as follows in Sydney N. Lederman, Alan W. Bryant & Michelle K. Fuerst, The Law of Evidence in Canada, 4th ed. (Markham: LexisNexis Canada, 2014) at p. 386:
In civil cases, an unfavourable inference can be drawn when, in the absence of an explanation, a party litigant does not testify, or fails to provide affidavit evidence on an application, or fails to call a witness who would have knowledge of the facts and would be assumed to be willing to assist that party. In the same vein, an adverse inference may be drawn against a party who does not call a material witness over whom he or she has exclusive control and does not explain it away. Such failure amounts to an implied admission that the evidence of the absent witness would be contrary to the party's case, or at least would not support it.
The adverse inference principle is discretionary and a judge is without a requirement to apply the principle where circumstances warrant. The basis for discretionary application of the adverse inference principle was explained by the Court of Appeal in Parris v. Laidley, 2012 ONCA 755, whereas it was stated:
[2] Drawing adverse inferences from failure to produce evidence is discretionary. The inference should not be drawn unless it is warranted in all the circumstances. What is required is a case-specific inquiry into the circumstances including, but not only, whether there was a legitimate explanation for failing to call the witness, whether the witness was within the exclusive control of the party against whom the adverse inference is sought to be drawn, or equally available to both parties, and whether the witness has key evidence to provide or is the best person to provide the evidence in issue.
Summary Comment
The adverse inference principle is akin to the common saying of, if you got it, then flaunt it; and is based on the expectation that if a litigant fails to flaunt evidence, the reason for failing to do so is, presumedly, because the evidence is unhelpful, and more likely harmful, to the case of the litigant.
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