"x x x.
THE BURDEN OF PROOF MAY BE ON THE PLAINTIFF OR THE DEFENDANT:
The party who alleges a fact has the burden of proving it. The burden of proof may be on the plaintiff or the defendant. It is on the defendant if he alleges an affirmative defense which is not a denial of an essential ingredient in the plaintiff’s cause of action, but is one which, if established, will be a good defense – i.e., an “avoidance” of the claim. Indeed, “in the final analysis, the party upon whom the ultimate burden lies is to be determined by the pleadings, not by who is the plaintiff or the defendant.” Burden of proof is the duty of any party to present evidence to establish his claim or defense by the amount of evidence required by law, which is preponderance of evidence in civil cases. The party, whether plaintiff or defendant, who asserts the affirmative of the issue has the burden of proof to obtain a favorable judgment. Upon the plaintiff in a civil case, the burden of proof never parts, though in the course of trial, once the plaintiff makes out a prima facie case in his favor, the duty or the burden of evidence shifts to the defendant to controvert the plaintiff's prima facie case; otherwise, a verdict must be returned in favor of the plaintiff. It is the burden of evidence which shifts from party to party depending upon the exigencies of the case in the course of trial. The term prima facie evidence denotes evidence which, if unexplained or uncontradicted, is sufficient to sustain the proposition it supports or to establish the facts. Prima facie means it is “sufficient to establish a fact or raise a presumption unless disproved or rebutted”
x x x."
