For purposes of sections 77-27,210 to 77-27,221:

(1) Debt means motor fuel taxes due and payable to the Department of Motor Vehicles pursuant to section 66-1405; and

(2) Refund means any Nebraska state income tax refund which the Department of Revenue determines to be due an individual, corporate, or business taxpayer. In the case of a joint income tax return, it shall be presumed that each partner to the marriage submitting such return contributed one-half of the earnings upon which the refund is based. The presumption may be contested by the state, the debtor, and the innocent spouse by virtue of the hearing process prescribed in section 77-27,216.