Is An Orignal Tortfeasor Who Is a proximate Cause of Injury Be Relieved of liabilty If the Ultimate Injuries Are Caused by Medical Malpractice ? In Blecker v. Wolbart (1985) 167 Cal. App. 3d 1195, 1200-1201 213 Cal. Rptr. 781, a pre-Proposition 51 case, a driver and motorcyclist collided, resulting in the motorcyclist's fracturing his forearm and thigh bone. (Blecker, supra, 167 Cal. App. 3d at p. 1199.) The motorcyclist later died during corrective surgery; the death was caused by the negligence of an anesthesiologist. After the driver settled with the motorcyclist's heirs on their wrongful death claims, the driver sued the anesthesiologist for indemnity. (Ibid.) Concluding the trial court erred in instructing that the driver was not a proximate cause of the motorcyclist's death, the reviewing court held the trial court should have instructed the jury on Ash v. Mortensen principles because that doctrine establishes the original tortfeasor is a proximate cause of the injury and is not relieved of liability because the medical malpractice is a substantial cause of the ultimate injuries. (Id. at pp. 1200-1204.)