What is the test for disclosing material facts in a medical malpractice case?

13 This instruction employs the objective test, as recommended in Cobbs v. Grant, supra, 8 Cal.3d 229, 245, 104 Cal.Rptr. 505, 502 P.2d 1. We note that the reasonably prudent person standard, though practical, tends to diminish the right of a patient to control his own body.

14 As a defense, the defendants would bear the burden of proof. "Material facts need not be disclosed where it is evident that the patient cannot evaluate the data because, for example, the patient is incompetent or exigent circumstances preclude adequate disclosure. ( [Cobbs v. Grant, supra,] at pp. 243-244, 104 Cal.Rptr. 505, 502 P.2d 1.) 'The burden of going forward with evidence of nondisclosure rests on the plaintiff. Once such evidence has been produced, then the burden of going forward with evidence pertaining to justification for failure to disclose shifts to the physician.' (Id., at p. 245 [104 Cal.Rptr. 505, 502 P.2d 1].)" (Truman v. Thomas, supra, 27 Cal.3d at p. 291, n. 3, 165 Cal.Rptr. 308, 611 P.2d 902.)