“Credibility assessment is not an exact science. In Baker-Warren v. Denault, 2009 NSSC 59 (N.S.S.C.) Forgeron J. noted that,
“It is not always possible to “articulate with precision the complex intermingling of impressions that emerge after watching and listening to witnesses and attempting to reconcile the various versions of events.” R. v. Gagnon, 2006 SCC 17, para. 20. I further note that “assessing credibility is a difficult and delicate matter that does not always lend itself to precise and complete verbalization.” R v. R.E.M., 2008 SCC 51, para. 49.”
In Christakos v. De Caires, 2016 ONSC 702 at para. 10, Nicholson J. adopted as helpful MacDonald J.’s following outline in Re Novak Estate, 2008 NSSC 283 (CanLII), 269 N.S.R. (3d) 84:
[36] There are many tools for assessing credibility:
a) The ability to consider inconsistencies and weaknesses in the witness’s evidence, which includes internal inconsistencies, prior inconsistent statements, inconsistencies between the witness’ testimony and the testimony of other witnesses.
b) The ability to review independent evidence that confirms or contradicts the witness’ testimony.
c) The ability to assess whether the witness’ testimony is plausible or, as stated by the British Columbia Court of Appeal in Faryna v. Chorny, 1951 CanLII 252 (BC CA), 1951 CarswellBC 133, it is “in harmony with the preponderance of probabilities which a practical [and] informed person would readily recognize as reasonable in that place and in those conditions”, but in doing so I am required not to rely on false or frail assumptions about human behaviour.
d) It is possible to rely upon the demeanour of the witness, including their sincerity and use of language, but it should be done with caution ( v. Mah, 2002 NSCA 99 (CanLII) [at paras.] 70-75).
e) Special consideration must be given to the testimony of witnesses who are parties to proceedings; it is important to consider the motive that witnesses may have to fabricate evidence. v. J.H.2005 CanLII 253 (ON CA), [2005] O.J. No. 39 (OCA) [at paras.] 51-56).
[37] There is no principle of law that requires a trier of fact to believe or disbelieve a witness’s testimony in its entirety. On the contrary, a trier may believe none, part or all of a witness’s evidence, and may attach different weight to different parts of a witness’s evidence (See R. v. D.R. [1966] 2 S.C.R. 291 at [para.] 93 and R. v. J.H. supra). [Emphasis in original.]
In Ouellette v. Udin, 2018 ONSC 4520 at para. 9, Shelston J. described credibility assessment as a “holistic undertaking incapable of precise formulation”. In Al-Sajee v Tawfic, 2019 ONSC 3857 at paras. 41 and 42, Chappel J. described assessing credibility as a complex task and provided a comprehensive summary listing what courts should consider in weighing and assessing the credibility and reliability of witnesses.”