Opinion ID: 1161718
Heading Depth: 1
Heading Rank: 2

Heading: the probative effect of the claimant's expert opinion

Text: The employer next urges that the claimant's medical evidence lacks probative value because it is based on the erroneous assumption that the decedent took nitroglycerin medication on a regular basis for several years following his 1972 cardiac episode. This contention presupposes that (a) the witness considered the assumed fact to be material to his opinion and (b) the causal nexus between the 1972 compensable heart injury and the decedent's death would be deemed broken if the assumed fact had been excluded from the witness' consideration. The employer's contention lacks legal merit for two reasons: (1) no showing has been made either that the allegedly erroneous assumption is false or unfounded, or that the claimant's medical expert actually considered it to be material to his opinion, [8] and (2) the employer advances no record-supported argument to show how the Wrongly assumed fact is or could have been material or even relevant to the expert's opinion on causation. [9] The law does not require the medical history considered by an expert to include all the facts the evidence tends to prove. The history assumed by the expert must substantially include those facts which the evidence tends to establish and which are not materially inconsistent with the adduced proof in the record. [10] The expert's opinion need only connect decedent's death to some extension or enlargement of the preexisting compensable injury. [11] The duty rests upon the cross-examiner either to elicit from the witness the failure to assume a fact conceded to be material or to show that the omitted fact is indeed indispensable so that its omission from the range of facts to be assumed is fatal to the probative value of the expert's opinion. [12] This responsibility of the cross-examiner clearly is cast by the Oklahoma Evidence Code [13] which has abrogated the earlier common-law requirement that an expert's opinion be elicited by means of a hypothetical question. [14]