In Winterholler v. Zolessi, 989 P.2d 621, 624-25 & 628 (Wyo. 1999), the plaintiffs retained a new medical expert witness after their original expert had to withdraw for health reasons. The plaintiffs inadvertently failed to give the defendant notice of the change in expert witnesses. The defendant learned of the substitution eight weeks before trial and moved to exclude his testimony. The district court granted the defendant's motion. On appeal, the Court reversed holding that the total exclusion of the expert's testimony created greater prejudice to the plaintiff than that incurred by the defendant despite the surprise inherent in the failure to disclose because the defendant still had eight weeks before trial to prepare when he learned of the change of experts. 989 P.2d at 628. The Court said, "where the authority to perform a proposed action rests within the discretion of the court we must allow considerable latitude in which it may exercise its discretion." This does not mean, however, that courts have "unrestrained power to act in an arbitrary manner." Id. "Fundamental to the concept of the rule of law is the principle that reason and justice shall prevail over the arbitrary and uncontrolled will of any one person. ...The meaning of the term 'discretion' itself imports that the action should be taken within reason and good conscience in the interest of protecting the rights of both parties and serving the ends of justice. It has always been the policy of our law to resolve doubts in favor of permitting parties to have their day in court on the merits of a controversy." (Id. at 628.) In Winterholler, the Court applied the following factors to determine whether late supplementation of expert disclosures was fair under the circumstances: (1) whether allowing the evidence would incurably surprise or prejudice the opposing party; (2) whether excluding the evidence would incurably prejudice the party seeking to introduce it; (3) whether the party seeking to introduce the testimony failed to comply with the evidentiary rules inadvertently or willfully; (4) the impact of allowing the proposed testimony on the orderliness and efficiency of the trial; and (5) the impact of excluding the proposed testimony on the completeness of the information before the court or jury. Id. On the basis of the particular circumstances presented in Winterholler, we held that the court abused its discretion in excluding expert testimony designated after the deadline. The Court said: "We are unable to find support in the record for the conclusion that the admission of the disputed testimony would incurably surprise or prejudice the defense. It is not difficult, however, to see that the exclusion of the testimony ...prejudiced the plaintiff's ability to present the merits of her ...claim." Id.