In this case, the respondent submits, counsel for the appellant C.B. focused her submissions on the text messages, referring
to the photo only as being at odds with G.D.’s testimony that
after the assault she did not go near C.B. for the rest of the evening and her claim of being traumatized by what occurred. Counsel
for the appellant A.C. did not refer to the photos at all in closing
 The respondent says that a review of the trial record as a
whole reveals that the photos were not central to an assessment
of the credibility of G.D. or the reliability of her evidence, and
thus were not material to the outcome of the case generally or
insofar as it related to the offences alleged by G.D. What is more,
the potential use of the evidence suggested by the appellants
engages myth-based reasoning, and thus cannot be invoked as a
pathway to proof of guilt.
The governing principles
 A claim of misapprehension of evidence takes in failures to
consider evidence relevant to a material issue, mistakes as to the
substance of evidence, and failures to give proper effect to evi-
dence: R. v. Morrissey (1995), 22 O.R. (3d) 514,  O.J. No.
639, 97 C.C.C. (3d) 193 (C.A.), at p. 218 C.C.C.
 Where a misapprehension of evidence is advanced as a
ground of appeal, an appellate court must consider first whether
the verdict from which the appeal is taken is unreasonable:
Morrissey, at p. 219 C.C.C. Provided the verdict is not unreasonable, we are required next to determine whether the misapprehension of evidence caused a miscarriage of justice within
s. 686( 1)(a)( iii) of the Criminal Code, R.S.C. 1985, c. C- 46. An
appellant who succeeds on this ground will have the underlying
conviction quashed and, in most cases, a new trial ordered:
Morrissey, at p. 219 C.C.C.
 The expansive scope of s. 686( 1)(a)( iii) includes errors involving a misapprehension of evidence. Such an error, like other errors
that fall within the section’s compass, is assessed by reference to its
impact on the fairness of the trial. When an error involving the misapprehension of evidence renders a trial unfair, s. 686( 1)(a)( iii)
demands that the conviction be quashed: Morrissey, at p. 221 C.C.C.
 Whether a misapprehension of evidence rendered a trial
unfair and resulted in a miscarriage of justice depends upon the
nature and extent of the misapprehension and its significance to
the verdict rendered by the trial judge. This is so because we
insist that a verdict be based exclusively on the evidence adduced
at trial: R. v. Lohrer,  3 S.C.R. 732,  S.C.J. No. 76,
2004 SCC 80, at para. 1; Morrissey, at p. 221 C.C.C.