Is there an instruction on wilful suppression of evidence in medical malpractice cases?

Defendant relies principally on Thor v. Boska (1974) 38 Cal.App.3d 558, 113 Cal.Rptr. 296, a case which did not involve an instruction on wilful suppression of evidence. Thor was a medical malpractice case in which [13 Cal.App.4th 993] defendant admitted during discovery he was unable to produce his original clinical records concerning his treatment of plaintiff. He "assume[d] that they were thrown away." (Id. at pp. 560-561, 113 Cal.Rptr. 296.) Defendant claimed, however, he had verbatim copies of the records. This claim was later called into question because plaintiff testified that when she first showed defendant the lump on her breast he drew a diagram showing its location. No such diagram appeared in the copies of the lost original records. (Id. at p. 561, 113 Cal.Rptr. 296.) Prior to trial, defendant admitted he had been negligent at some point in his treatment of plaintiff and on the strength of that admission obtained a ruling from the trial court that any reference to the unavailability of his original records would be unduly prejudicial. (Ibid.)