Haw. Rev. Stat. § 554B-11: Exemption of third person from liability.

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

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

(2) The propriety of, or the authority under this chapter for, any action of the purported custodial trustee;

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

(4) The propriety of the application of any property delivered to the purported custodial trustee.