evidence at trial, or absence of an explanation, can result in the
rejection of evidence that would otherwise be admissible on
appeal: Truscott, at para. 93. Where the proposed fresh evidence
was available but not tendered at trial because of tactical reasons
thought justifiable by competent counsel, an additional degree of
cogency is necessary before the proposed evidence may be
received on appeal: R. v. McDonald,  O.J. No. 3498, 2017
ONCA 568, 351 C.C.C. (3d) 486, at para. 148; Truscott, at para. 102.
The principles applied
 As I will explain, I would admit the fresh evidence. In my
respectful view, it satisfies the conditions precedent for reception
of fresh evidence and should not be excluded for want of due dili-
gence at trial.
 In this case, the fresh evidence extends beyond evidence
whose purpose is to impeach findings of fact made at trial. The
expert opinion of Marty Musters is tendered for that purpose, but
not so the affidavit and cross-examination of C.B.’s trial counsel.
Its target is the issue of due diligence whose failure may result in
the exclusion of evidence that satisfies the prerequisites for
 First, the expert opinion of Marty Musters.
 No dispute arises about the admissibility of the expert
opinion of Marty Musters under the operative rules of evidence.
He is a qualified forensic examiner whose report would be admissible at the conclusion of the two-step analysis put in place by
White Burgess Langille Inman v. Abbott and Haliburton Co.,
 2 S.C.R. 182,  S.C.J. No. 23, 2015 SCC 23.
 A critical issue at trial on which the outcome depended
was the credibility of the complainants and the reliability of their
account of non-consensual conduct on the part of both appellants,
which the Crown alleged constituted proof of the offences
charged. This evidence was vigorously challenged by the defence.
Among the methods of challenge was cross-examination of the
complainants on contemporaneous text messages (D.P.) and photographs (G.D.), which were said to be at odds with the complainants’ accounts of relevant events. And essential to impeachment
on this basis was the authenticity of those text messages and photographs employed in the impeachment process.
 The expert opinion of Marty Musters is relevant to the
authenticity of the text messages and photographs used as
impeachment mechanisms. His opinion establishes the nexus
between the texting partners, D.P. and the appellant C.B., and the
contemporaneity and source of the photographs. It tends to show
that D.P.’s denial of authorship could be false.