Adverse Inference — An inference is similar to a presumption, adverse to the concerned party and drawn from silence or absence of adduced evidence.
A judge has discretion to draw an inference, but it must be supported by evidence. Generally, all evidence is weighed according to the proof that one side is capable of producing and the other side is capable of refuting or rebutting.
The principle applies in criminal cases in two ways: an adverse inference may be drawn for failure to produce a witness reasonably assumed to be favourably disposed to that party; and the inference may be drawn against a party who has exclusive control over a material witness, but fails to produce the witness.
In “The Law of Evidence in Canada, 2nd ed.,” Sopinka and Lederman describe the principle in civil matters:
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.
R. v. Noble, 1997 CanLII 388 (SCC),  1 SCR 874
Did the trial judge err in drawing an adverse inference from the accused’s failure to give evidence?
Chippewas of Kettle & Stony Point First Nation v. Shawkence, 2005 FC 823 (CanLII)
In civil law: Was the Adjudicator’s failure to draw an adverse inference regarding a party’s failure to testify a patently unreasonable error in law or otherwise constitute an excess of jurisdiction?
Canada Evidence Act, RSC 1985, c C-5, s 4(6)
“The failure of the person charged, or of the wife or husband of that person, to testify shall not be made the subject of comment by the judge or by counsel for the prosecution.”