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Adverse Inference:
Negative Presumptions for Failing to Present Evidence
Last Updated: August 23 2026
Question: In Ontario civil court, how do adverse inferences work when a party fails to call a witness or produce evidence?
Answer: PKM Legal Services helps Ontario clients with evidence and procedure issues tied to adverse inference. An adverse inference is a discretionary evidentiary inference a judge may draw when a party does not testify, does not call a key witness, or does not produce relevant documents the party could reasonably be expected to provide, and there is no adequate explanation. The idea is that if evidence was within that party’s control and would likely help their case, the absence suggests it could be harmful or at least not supportive. Courts look at the full context, including whether the witness or documents were under the party’s exclusive control, whether the evidence was equally available to both sides, and whether there was a legitimate reason for not presenting it. If you are facing an adverse inference risk in your case, contact (519) 410-5250 with PKM Legal Services for paralegal guidance in Ontario.
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Understanding the Principle of Adverse Inference as an Evidentiary Rule Arising from Failure to Produce Evidence
An adverse inference, which may sometimes also be called a negative inference, may occur a litigant fails to provide evidence or fails to provide testimony that was reasonably expected to come from the litigant. Where the litigant fails to provide the expected evidence or the expected testimony, the court may presume that the litigant avoided the evidence or testimony because such was unfavourable.
Note: Please contact PKM Legal Services by phone at: (519) 410-5250 to discuss any specific questions that you may have.
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 principle of adverse inference is the legal version of saying, if you got it, then flaunt it; and, if a party fails to do so, the court may presume that a party who fails to use evidence does so because the evidence would be unfavourable.
NOTE: A significant quantity of online searches featuring “lawyers near me” or “best lawyer in” frequently indicates a pressing necessity for competent legal assistance rather than a distinct occupational label. In Ontario, accredited paralegals fall under the regulation of the same Law Society that governs lawyers and possess the authority to advocate for clients in specific litigation issues. Core elements of this position include advocacy, legal evaluation, and procedural expertise. PKM Legal Services provides legal advocacy under its sanctioned mandate/scope, focusing on strategic alignment, evidence preparation, and persuasive representation aimed at attaining efficient and advantageous outcomes for clients.
