NUMBER OF WITNESSES
The preponderance, or weight of evidence, is not necessarily with the greater number of witnesses.
The testimony of one witness worthy of belief is sufficient for the proof of any fact and would justify a verdict in accordance with such testimony, even if a number witnesses have testified to the contrary. If, from the whole case, considering the credibility of witnesses, and after weighing the various factors of evidence, you believe that there is a balance of probability pointing to the accuracy and honesty of the one witness, you should accept his testimony.
NEV. J.I. 3.01