An appellate court will not readily interfere with a trial court's findings on credibility of witnesses in the absence of established misdirection, as the trial court is better positioned to assess witness credibility. Where an accused admits the existence of certain physical evidence (in this case, the pangolin scales and leopard skins in the bag), there is no need to produce that evidence at trial to prove an undisputed fact. Possession of specially protected animals or their products can be proved by circumstantial evidence including the accused being found carrying the items, offering them for sale, and being present alone at the point of arrest. A defence version that contraband belonged to another person who conveniently disappeared is implausible where no reasonable explanation is given for why that person was not pursued or located.