In Throop v. F.E. Young & Co., 94 Ariz. 146, 382 P.2d 560 (1963), the defendant, a personal representative of the deceased driver, claimed that the driver suffered a sudden heart attack. Id. at 156, 382 P.2d at 566. The plaintiff sought to introduce evidence that the defendant's doctor had told the driver to refrain from driving due to his heart condition. Id. When the defendant attempted to block the testimony by claiming the privilege, the court concluded that the defendant could not block inquiry into the issue he had raised. Id. at 157-58, 382 P.2d at 567-68. In short, waiver occurs "when the conduct (though not evincing that intention) places the claimant in such a position, with reference to the evidence, that it would be unfair and inconsistent to permit the retention of the privilege. It is not to be both a sword and a shield." Id. at 158, 382 P.2d at 568.