What is the effect of the onus factor in determining the outcome of a case?

In the context of this case, it is worthwhile to note the role onus plays as a factor in coming to a decision. This has been noted in the following terms: But onus as a determining factor of the whole case can only arise if the tribunal finds the evidence pro and con so evenly balanced that it can come to no such conclusion. Then the onus will determine the matter. But if the tribunal, after hearing and weighing the evidence, comes to a determinate conclusion, the onus has nothing to do with it, and need not be further considered. (Robins v. National Trust, supra, at pp. 519-520)