Experts can give opinions on the final issue in a case

Prior to the adoption of this rule Hawaii adhered to the "ultimate issue" exclusion, see Friedrich v. Department of Transportation, 60 H. 32, 586 P.2d 1037 (1978); Sherry v. Asing, 56 H. 135, 147, 531 P.2d 648, 657 (1975); Cozine v. Hawaiian Catamaran, Ltd., 49 H. 77, 412 P.2d 669 (1966). The abolition of the "ultimate issue" rule does not leave the court without safeguards. First, the present rule requires that the testimony be "otherwise admissible." Second, under the limitations of Rules 701 and 702 supra, opinion testimony must be helpful to the trier of fact. Third, under Rule 705 infra, the court at its discretion may require prior disclosure of the underlying facts or data upon which the opinion is based. Finally, under Rules 403 and 703 supra, the court has discretion to exclude the testimony entirely if it is prejudicial, confusing, misleading, unnecessarily cumulative, or lacking in trustworthiness. As the Advisory Committee's Note to Fed. R. Evid. 704 puts it: These provisions afford ample assurances against the admission of opinions which would merely tell the jury what result to reach, somewhat in the manner of the oath-helpers of an earlier day. They also stand ready to exclude opinions phrased in terms of inadequately explored legal criteria. Thus the question, "Did T have the capacity to make a will?" would be excluded, while the question, "Did T have sufficient mental capacity to know the nature and extent of his property and the natural objects of his bounty and to formulate a rational scheme of distribution?" would be allowed.