The binding legal principles established are: (1) For a single witness's evidence to found judgment in civil proceedings, it must be credible and satisfy the court that truth has been told, despite any shortcomings; contradictory evidence on material issues, particularly when coupled with disavowal of prior testimony and avoidance of innocuous concessions, destroys credibility. (2) Where a defendant admits conduct but pleads justification (private defence/necessity), the onus shifts to the defendant to establish the defence, but the plaintiff bears the evidentiary burden regarding disputed facts such as location and circumstances. (3) The defence of necessity/private defence in crowd control situations requires: (a) reasonable grounds for believing there was imminent danger to life, limb or property; (b) use of proportionate force having regard to the nature and extent of danger, likelihood of serious injury, and value of property threatened; the court must avoid being an "armchair critic" and consider circumstances operating on the actor's mind at the time. (4) For volenti non fit injuria to succeed: the plaintiff must have had knowledge of the risk, appreciated its ambit, and consented (expressly or impliedly); where the plaintiff foresaw and appreciated the danger, consent will be implied; the injury must result from materialization of the risk that was subjectively foreseen and assumed. (5) An appellate court will only interfere with factual findings and credibility assessments where there is demonstrable material misdirection by the trial court.