In Egurrola v. Szychowski, 95 Ariz. 194, 388 P.2d 242 (1964), plaintiff had sued the driver of the car in which she had been a passenger for the injuries she had suffered in an accident involving another vehicle. Pursuant to the parties' stipulation, plaintiff introduced into evidence a covenant in which she had agreed not to sue the driver of the other car in exchange for $ 10,000. She then sought unsuccessfully to introduce a separate letter from that driver's attorney stating the coverage limit on the driver's automobile liability policy was $ 10,000, fearing that introduction of only the covenant, "unexplained by the letter, would imply some ill-defined or well-concealed defect in the plaintiffs' case on the question of liability." Egurrola, 95 Ariz. at 198, 388 P.2d at 244. The supreme court noted that the plaintiff's predicament had arisen from her introduction into evidence of the covenant, which was not otherwise admissible. It was inadmissible, the court ruled, based on the principle of joint tortfeasor liability. The court explained that the proper method of accounting for settlement proceeds is to subtract them from the total damages awarded by the jury. Egurrola was decided long before comparative fault was the law in Arizona. See A.R.S. 12-2505; 1984 Ariz. Sess. Laws, ch. 237, 7.