Any sums in a joint account may be paid, on request, to any party without regard to whether any other party is incapacitated or deceased at the time the payment is requested. Payment may not be made to the personal representative or heirs of a deceased party unless:
(1) Proof of death is presented to the credit union, showing that the decedent was the last surviving party; or
(2) There is no right of survivorship under ORS 723.480.