Leach v. Insurance Corporation of British Columbia
were summarized by Dillon J. in Bradshaw v. Stenner, 2010 BCSC 1398 at
para. 186, aff’d 2012 BCCA 296, as follows:
 Credibility involves an assessment of the
trustworthiness of a witness’ testimony based upon the
veracity or sincerity of a witness and the accuracy of the
evidence that the witness provides (Raymond v. Bosanquet
(Township) (1919), 59 S.C.R. 452, 50 D.L.R. 560 (S.C.C.)).
The art of assessment involves examination of various factors
such as the ability and opportunity to observe events, the
firmness of his memory, the ability to resist the influence of
interest to modify his recollection, whether the witness’
evidence harmonizes with independent evidence that has
been accepted, whether the witness changes his testimony
during direct and cross-examination, whether the witness’
testimony seems unreasonable, impossible, or unlikely,
whether a witness has a motive to lie, and the demeanour of a
witness generally (Wallace v. Davis,  31 O.W.N. 202
(Ont. H.C.); Faryna v. Chorny,  2 D.L.R. 354 (B.C.C.A.)
[Faryna]; R. v. S.(R.D.),  3 S.C.R. 484 at para.128
(S.C.C.)). Ultimately, the validity of the evidence depends on
whether the evidence is consistent with the probabilities
affecting the case as a whole and shown to be in existence at
the time (Faryna at para. 356).
If the plaintiff’s evidence of the changes in his or her physical, mental,
and or emotional state following the accident is not convincing, the opinions
of any experts who have relied on the veracity of that evidence will be
undermined. Credibility of a plaintiff in a personal injury claim is therefore of
great importance, especially when the majority of the symptoms are not
easily seen or measured.
However, if the evidence withstands challenge and the plaintiff is
found to be credible, the fact that the case is founded on subjective as
opposed to objective evidence will make no difference because a plaintiff with
subjective symptoms is no less entitled to compensation than one with
objective symptoms, provided the plaintiff’s losses are proven.
 As I discuss the evidence from both expert and lay witnesses throughout this
decision, I provide my assessment of their credibility and reliability based on the
considerations articulated by Wilson J. in Wells.
Expert Evidence Respecting the Accident
Gerald Sdoutz: Vehicle Incident Report
 The plaintiff adduced the evidence of Gerald Sdoutz, an accident
reconstruction engineer. Mr. Sdoutz is a professional mechanical engineer with
Bachelor degrees in Science and Applied Science.