How have courts dealt with cross-actions in a medical malpractice case?

Thus, for example, in County of Contra Costa v. Kaiser Foundation Health Plan, Inc. (1996) 47 Cal.App.4th 237, 54 Cal.Rptr.2d 628, the court considered the situation in which a plaintiff, who had been hit by a car, sued her health insurer for medical malpractice as well as other defendants allegedly liable for the accident. The co-defendants brought claims for equitable indemnity against the insurer, who moved to compel arbitration of the plaintiff's action and the co-defendants' cross-actions. While the plaintiff's action against the insurer was clearly arbitrable, as the insurance contract contained an arbitration clause, the co-defendants' cross-actions were not. The court concluded that the co-defendants could not be compelled to arbitrate because there was no preexisting relationship between the co-defendants and the insured plaintiff which would have enabled the insured plaintiff to bind them when she agreed to the arbitration clause. ( Id. at p. 243, 54 Cal.Rptr.2d 628.) Yet, the same result could have been reached on the theory that the co-defendants' cross-actions against the health insurer were not based on the contract between the insurer and the plaintiff.