Credibility-Every trial lawyer can tell you how he or she had a great case, except the #%~|\#* Judge did not believe a word your client said!
It often comes down to who a Judge believes and accepts as a credible witness, as opposed to the opposite. I have seen cases where a judge did not believe the witnesses on either side.
The issue of conflicting evidence given by witnesses for each side is one that requires a trial by a judge with or without a jury, as it is near impossible to judge credibility from reading affidavits- the judge needs to observe and listen carefully to not only what the witness says, but how they appear doing it as well.
The law of credibility can be summarized as follows:
In such cases where the parties assert inconsistent versions of the events at issue, it is useful to consider a number of factors including the attitude and demeanour of the witness whose testimony is at issue, the extent to which his or her evidence agrees with that of third parties who have no stake in the outcome of the lawsuit, or of other objective evidence, the likelihood or objective probability that the evidence being advanced is accurate or inaccurate, the interest of the witness has in the outcome of the case, and the ability of the witness to perceive, remember and articulate what he or she is testifying about.
] In Faryna v. Chorny  2 D.LR. 354 at 357, 4 W.W.R. (N.S.) 171 (B.C.C.A.), O’Halloran J.A. made the following observation:
The credibility of interested witnesses, particularly in cases of conflict of evidence, cannot be gauged solely by the test of whether the personal demeanour of the particular witness carried conviction of the truth. The test must reasonably subject his story to an examination of its consistency with the probabilities that surround the currently existing conditions. In short, the real test of the truth of the story of a witness in such a case must be its harmony with the preponderance of the probabilities which a practical and informed person would readily recognize as reasonable in that place and in those conditions.