Judges may not engage in speculative reasoning or supplement facts based on personal experience

R. v. MacIsaac, 2015 ONCA 587:

[46]       It was open to the trial judge to draw inferences that reasonably and logically flowed from the facts established by the evidence.  But it was an error of law to draw inferences that did not flow logically and reasonably from established facts, because doing so draws the trial judge into the impermissible realms of conjecture and speculation: R. v. Morrissey (1995), 22 O.R. (3d) 514 (C.A.), at pp. 530-531.

[47]       Where a trial judge has employed speculative reasoning, unless the Crown can demonstrate that the error caused no substantial wrong or miscarriage of justice, the convictions tainted by that error must be quashed: Morrissey, at p. 531.

[48]        The examples of the trial judge’s speculative reasoning cited above were not on peripheral areas; the issues she was dealing with were central to the case and were highly relevant to the determination of whether the Crown had proven the offence beyond a reasonable doubt. For example, evidence of the appellant’s intentions as he skated toward the complainant was critical in deciding if this was a premeditated hit or an accidental collision.  The evidence of defence witnesses was rejected in whole or in part based upon the trial judge’s understanding of hockey strategy and her views regarding on-ice injures, unaided by any expert testimony. While an isolated example of speculative reasoning may not have sufficed to render the trial unfair, I agree with the submission of the appellant that the trial judge rejected evidence that was capable of raising a reasonable doubt based on this series of speculative conclusions, and that this reasoning directly lead to her decision to convict.

[49]       The appellant was entitled to a determination of his guilt or innocence based on the evidence at trial, not on the hockey experience of the trial judge or her understanding of the injuries to be expected from various types of on-ice collisions. An accused in a criminal proceeding must make any number of strategic decisions based upon the evidence that is presented at trial. He or she bases decisions about what questions to ask, what evidence to lead, whether to testify and what arguments to advance, based on the state of play of the trial. A trial judge ought not to supplement and supplant the evidentiary record, except in very limited situations where taking judicial notice is permitted. 

[50]       This was not a case in which judicial notice could be taken of the disputed facts. A court can take judicial notice of a fact only if it is: (1) so notorious or generally accepted that no reasonable person would disagree; or (2) capable of immediate demonstration by reference to sources of indisputable accuracy (R. v. Find, 2001 SCC 32, [2001] 1 S.C.R. 863, at para. 48, citing R. v. Potts (1982), 66 C.C.C. (2d) 219 (Ont. C.A.)). Due to concerns about possible prejudice to the accused, the Supreme Court has set strict limits on the use of judicial notice to determine adjudicative facts in criminal trials: R. v. Spence, 2005 SCC 71, [2005] 3 S.C.R. 458, at paras. 61-62. Those concerns have been echoed more recently by this court: R. v. Perkins, 2007 ONCA 585, 223 C.C.C. (3d) 289, at paras. 37-42.