La preuve de faits similaires & la collusion

R. v. Wilkinson, 2017 ONCA 756

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[37]      In fairness to the trial judge, there is a lack of precision in the case law concerning the treatment of unconscious collusion at the admissibility stage. In Handy and Shearing, the Court addressed collusion in its most literal sense. In both cases, it was alleged that the allegations were fabricated, and that two or more witnesses had agreed to proceed with a false story. In its treatment of this issue, the Court used different terminology to describe the same thing. Handy employs the terms “collusion”, “actual collusion” and “concoct.” Shearing refers to “collusion”, “concoction” and “concoct.” Neither case directly discusses “unconscious” or “inadvertent” collusion or tainting of similar fact witnesses.[1]

[38]      However, decisions from this court support the view that actual collusion and unconscious collusion ought to be treated the same way at the admissibility stage. In R. v. F. (J.) (2003), 2003 CanLII 52166 (ON CA), 177 C.C.C. (3d) 1 (Ont. C.A.), Feldman J.A. discusses both types of collusion, at para. 77:

The trial judge's finding that B.H. was sincere, a "straight shooter", and not influenced by E.T. and the others, fails to take into account that collusion and discussion among witnesses can have the effect of tainting a witness's evidence and perception of events innocently or accidentally and unknowingly, as well as deliberately and intentionally. The reliability of a witness's account can be undermined not only by deliberate collusion for the purpose of concocting evidence, but also by the influence of hearing other people's stories, which can tend to colour one's interpretation of personal events or reinforce a perception about which one had doubts or concerns. [Emphasis added.]

[39]       R. v. B. (C.) (2003), 2003 CanLII 32894 (ON CA), 171 C.C.C. (3d) 159 (Ont. C.A.) fosters the same approach. As the court said at paras. 40-41:

Collusion can arise both from a deliberate agreement to concoct evidence as well as from communication among witnesses that can have the effect, whether consciously or unconsciously, of colouring and tailoring their descriptions of the impugned events. In this case there was evidence of, or at least the opportunity for collusion in the various discussions regarding the incidents reported by the complainants. Furthermore, taken together with the anger regarding the dismissal and pay issues between one complainant and the appellant and the joint lawsuit by the complainants for damages, there was clearly an air of reality to the possibility of collusion in this case.

It was therefore incumbent on the trial judge, in considering the admissibility of the similar fact evidence, to determine whether he was satisfied on a balance of probabilities that the evidence was not tainted by collusion. In his ruling admitting the similar fact evidence, the trial judge did specifically refer to the fact that the witnesses had discussed some of the evidence with each other. [Emphasis added.]

Ultimately, the case was decided on the basis of inadequacies in the trial judge’s instructions to the jury. Nevertheless, this passage supports the conclusion that, when there is an air of reality to conscious or unconscious collusion, the similar fact evidence will not be admissible unless the Crown proves on a balance of probabilities that conscious or unconscious collusion has not tainted the testimony.  

[40]      Further support for the appellant’s position is found in the cases that require trial judges to instruct juries on the possibility of collusion, both actual and unconscious. As Feldman J.A. wrote in F. (J.), at para. 86:

Once admitted, the jury must still be warned to assess the evidence carefully and to consider whether it can be considered reliable given the possibility of deliberate or accidental tainting by collusion among the witnesses.

See also R. v. M.B., 2011 ONCA 76, 267 C.C.C. (3d) 72: and David Watt, Watt’s Manual of Criminal Jury Instructions, 2nd ed. (Toronto: Carswell, 2015), pp. 367-368 (Final 28-E – Collusion Amongst Similar Act Witnesses).