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. In the absence of knowledge to the contrary, the third person is not responsible for determining:
(1) The validity of the purported custodial trustee's designation;
(2) The propriety of, or the authority under the Nebraska Uniform Custodial Trust Act for, any action of the purported custodial trustee;
(3) The validity or propriety of an instrument executed or instruction given pursuant to the act either by the person purporting to make a transfer or declaration or by the purported custodial trustee; or
(4) The propriety of the application of property vested in the purported custodial trustee.