Haw. Rev. Stat. § 553A-16: Exemption of third person from liability.

A third person in good faith and without court order may act on the instructions of or otherwise deal with any person purporting to make a transfer or purporting to act in the capacity of a custodian and, in the absence of knowledge, is not responsible for determining:

(1) The validity of the purported custodian's designation;

(2) The propriety of, or the authority under this chapter for, any act of the purported custodian;

(3) The validity or propriety under this chapter of any instrument or instructions executed or given either by the person purporting to make a transfer or by the purported custodian; or

(4) The propriety of the application of any property of the minor delivered to the purported custodian.