Credibility and reliability are not the same thing.  “Credibility has to do with a witness’s veracity, reliability with the accuracy of the witness’s testimony. Accuracy engages consideration of the witness’s ability to accurately

i.                 observe;

ii.                recall; and

iii.               recount events in issue.
Thus, credibility is not a proxy for reliability: a credible witness may give unreliable evidence.
Like credibility, reliability is a factual determination. Evaluations of witness credibility and the reliability of evidence are within the province of the trial judge, as it is the trial judge who has the opportunity to hear and observe all of the witnesses.
While a trial judge’s findings on the credibility and reliability are entitled to deferencea failure of the trial judge to articulate how credibility or reliability concerns are resolved, particularly in the face of significant inconsistencies in a complainant’s testimony, may constitute a reversible error, as an accused is entitled to know why the trial judge is left with no reasonable doubt.

Stuart O’Connell, O’Connell Law Group (All rights reserved to author).

R. v. H.C., 2009 ONCA 56, 241 C.C.C. (3d) 45, at para. 41.
H.C., at para. 41; R. v. Morrissey (1995), 22 O.R. (3d) 514 (C.A.), at p. 526.
R. v. Slatter, 2019 ONCA 807, at para. 118, per Pepall J.A. (dissenting, but not on this point).
R. v. Slatter, 2019 ONCA 807, at paras. 70-72; R. v. Dinardo, 2008 SCC 24 (CanLII), [2008] 1 S.C.R. 788, at para. 31; See also R. v. A.M., 2014 ONCA 769, 123 O.R. (3d) 536, at para. 18: See also R. v. D.H., 2016 ONCA 569, 338 C.C.C. (3d) 251, at para. 35: “major inconsistencies in the evidence of material witnesses” should be addressed and explained.