To the extent that the trial court's decision is dependent upon interpretation of court rule[s], such interpretation is a question of law, which [the appellate] court reviews de novo." State v. McDonnell, 141 Hawai‘i 280, 289, 409 P.3d 684, 693 (2017) (citing Barcai v. Betwee, 98 Hawai‘i 470, 479, 50 P.3d 946, 955 (2002) ). B. Plain Error Review

In State v. McDonnell, 141 Hawai'i 280, 409 P.3d 684 (2017), the supreme court reviewed a challenge to Dr. Bivens's testimony in a different child sexual abuse case. There, Dr. Bivens "testified with regard to the dynamics of child sexual abuse, including delayed reporting and underreporting by victims of abuse, and 'grooming' techniques typically used by abusers.

To the extent that the trial court's decision is dependent upon interpretation of court rule[s], such interpretation is a question of law, which [the appellate] court reviews de novo." State v. Engelby, 147 Hawai'i 222, 231, 465 P.3d 669, 678 (2020) (quoting State v. McDonnell, 141 Hawai'i 280, 289, 409 P.3d 684, 693 (2017)). Appellate courts apply the right/wrong standard in reviewing challenges to a court's relevancy decisions.

Specialized knowledge testimony imparts "knowledge not possessed by the average trier of fact who lacks the expert's skill, experience, training, or education." State v. McDonnell, 141 Hawai‘i 280, 291, 409 P.3d 684, 695 (2017) (citation omitted). HRE Rule 702 (1992) provides:

This court has recognized that expert testimony is helpful in child sex abuse cases in order to aid the jury in assessing the distinct dynamics and behavior of child sexual abuse victims, which is not within the common understanding of jurors. See Batangan, 71 Haw. at 558, 799 P.2d at 52 (concluding that certain "expert testimony explaining ‘seemingly bizarre’ behavior of child sex abuse victims is helpful to the jury and should be admitted"); State v. McDonnell, 141 Hawai‘i 280, 409 P.3d 684 (2017); State v. Kony, 138 Hawai‘i 1, 3, 375 P.3d 1239, 1241 (2016). In Hirata, such an expert testified.

However, HRE Rule 403 is a poor vehicle for banning this testimony, as the rule is designed for case-by-case application in the trial courts. See State v. McDonnell, 141 Hawai‘i 280, 293, 409 P.3d 684, 697 (2017) ("The determination of the admissibility of relevant evidence under HRE Rule 403 is eminently suited to the trial court's exercise of its discretion because it requires a ‘cost-benefit calculus’ and a ‘delicate balance between probative value and prejudicial effect.’ " (quoting State v. Balisbisana, 83 Hawai‘i 109, 114, 924 P.2d 1215, 1220 (1996) ); United States v. Gomez, 763 F.3d 845, 857 (7th Cir. 2014) ("Because each case is unique, Rule 403 balancing is a highly context-specific inquiry; there are few categorical rules.").

Id. at 557-58, 799 P.2d at 51-52. In State v. McDonnell, 141 Hawai‘i 280, 409 P.3d 684 (2017), the supreme court held that expert testimony on delayed reporting, tunnel memory, and incomplete disclosure was relevant because it "assisted the jury in understanding the ‘seemingly bizarre behavior’ exhibited by [the child]." Id. at 292, 409 P.3d at 696.

Under these circumstances, the court's evidentiary ruling about Dr. Natarajan was harmless error. See State v. McDonnell, 141 Hawai'i 280, 297-98, 409 P.3d 684, 701-02 (2017) (stating that error in admitting expert's testimony on statistics was harmless because "[e]rror should not be viewed in isolation and considered purely in the abstract, but must be examined in light of the entire proceedings and given the effect to which the whole record shows it is entitled" (quotation marks omitted)).

Trial error is not to be viewed in isolation or considered in the abstract; it must be examined in light of the entire proceeding and given the effect to which the whole record shows it is entitled. State v. McDonnell, 141 Hawai‘i 280, 297–98, 409 P.3d 684, 701–02 (2017) (citation omitted). We must determine whether there is a reasonable possibility the error might have contributed to the conviction.

The State's arguments are thus deemed waived. See State v. McDonnell, 141 Hawai‘i 280, 295, 409 P.3d 684, 699 (2017) ("Generally, if a party does not raise an argument at trial, that argument is deemed waived on appeal.") (citing State v. Moses, 102 Hawai‘i 449, 456, 77 P.3d 940, 947 (2003) ); State v. Harada, 98 Hawai‘i 18, 30, 41 P.3d 174, 186 (2002) (concluding that the prosecution failed to preserve its exigent circumstances claim and thus waived it).