HRS § 702.1
RULE 702.1 COMMENTARY
This rule has no counterpart in Fed. R. Evid. It is modeled on Cal. Evid. Code §721.
Subsection (a): An expert witness differs from a lay witness principally in his ability to draw and to testify to inferences that are beyond the competence of the trier of fact. In addition, the expert is not restricted to firsthand knowledge and may base his opinions and inferences on a wide variety of data and facts perceived by him or made known to him, whether or not they are admissible in evidence, see Rule 703 infra.
Such a broad testimonial range suggests the need for an equally broad cross-examination, and subsection (a) of this rule provides the appropriate latitude. Subsection (a) restates existing law, see McCandless v. Waiahole Water Co., Ltd.,35 Haw. 314, 320 (1940).
Subsection (b): This subsection clarifies the permissible use of texts and treatises on cross-examination. Hawaii courts have long recognized that an expert may be subjected to cross-examination concerning publications upon which he has relied, see Fraga v. Hoffschlaeger,26 Haw. 557, 567 (1922).
Subsection (b)(2) parallels Rule 803(b)(18) which, agreeably with Fed. R. Evid. 803(18), exempts from the hearsay exclusion those texts and treatises that are used on cross-examination. The criterion of Rule 803(b)(18) is that the material be "established as a reliable authority," regardless of whether or not the witness has relied on it. Use of such material on cross-examination was approved in Ruth v. Fenchel, 37 N.J. Super. 295, 117 A.2d 284 (1955), aff'd, 21 N.J. 171, 121 A.2d 373 (1956). The Ruth case was cited approvingly by Chief Justice Richardson in Tittle v. Hurlbutt, 53 H. 526, 534, 497 P.2d 1354, 1359 (1972), in connection with the following statement: "This court recognizes the wisdom of enlarging the scope of use of medical texts on cross-examination." That wisdom is codified in subsection (b).
Section 704-416 overrides this rule. 71 H. 591, 801 P.2d 27.