Missing evidence? Assume the worst

July 21, 2022

One of the common issues that come up in many types of disputes is when an opposing party refuses to produce relevant evidence that is within their control. Thankfully our legal system has rules that deal with this, or else parties could simply just not submit evidence which they know would hurt their case.

Judges and decision-makers are allowed to draw inferences when determining factual matters. Generally, an inference is an educated guess; it is the process of forming a conclusion based on the information that you have. [1] The Supreme Court of Canada has stated that a judge “may make inferences of fact based on the undisputed facts before the court, as long as the inferences are strongly supported by the facts”. [2]

The common law principle of adverse inference

When such an inference is applied in cases where a party is refusing to produce evidence, it is called an “adverse inference”. A decision maker may draw an adverse inference from a party's failure to produce relevant documents they were required to produce or should have produced.

This principle is well-established and explained in detail in the classic by Wigmore, “Evidence in Trials at Common Law”:

...The failure to bring before the tribunal some circumstance, documents, or witness, when either the party himself or his opponent claims that the facts would thereby be elucidated, serves to indicate, as the most natural inference, that the party fears to do so, and this fear is some evidence that the circumstance or document or witness, if brought, would have exposed facts unfavourable to the party. These inferences, to be sure, cannot fairly be made except upon certain conditions; and they are also open always to explanation by circumstances which make some other hypothesis a more natural one than the party's fear of exposure. But the propriety of such an inference in general is not doubted. [3]

Adverse inferences also apply to administrative tribunals

This does not just apply to civil cases, but also in administrative law tribunals such as the Immigration and Refugee Board or the Landlord and Tenant Board. Even though there is no formal process in these tribunals for submitting evidence, as a common law principle, the adverse inference still come into play whenever a case hinges on the determination of evidence. For instance, in Ma v Canada (Minister of Citizenship and Immigration), the Federal Court stated:

Reasonableness dictates that in the case of the Immigration and Refugee Board (and all its divisions), although the rules of evidence in its regard are relaxed, nevertheless, when evidence is available, or could be made available but not produced, or when a person can testify, is given the opportunity to testify, but does not testify, then an adverse inference can be drawn. [4]

With that said, whether in civil litigation or an administrative tribunal, a decision-maker will usually assume that the reason a party has not produced evidence in their control is because they know it will not help their case (and most likely harm it). In life, we're told its always wise to be humble, but that advice should never be taken in litigation. The general rule is, if you have the evidence, then flaunt it!




[1] Definition of “Inference”, Merriam-Webster Dictionary.
[2] Canada (Attorney General) v. Lameman, 2008 SCC 14, at para 11
[3] John H. Wigmore, “Evidence in Trials at Common Law”, 1979 (Chadbourn Rev.) at vol. 2, 285, page 192
[4] Ma v. Canada (Minister of Citizenship and Immigration), 2010 FC 509, at para 2