(1) For the purposes of determining whether an * adjustment arises under section 21 - 5 or 21 - 15 for the whole or a part of a debt relating to a * taxable supply or * creditable acquisition for which a * representative of an * incapacitated entity is liable to pay GST, or is entitled to an input tax credit, under section 58 - 10:
(a) the adjustment cannot arise if, when the whole or part of the debt is written off, or has been * overdue for 12 months, the representative * accounts on a cash basis; but
(b) it does not matter whether the incapacitated entity accounts on a cash basis at that or any other time.
(2) This section has effect despite subsections 21 - 5(2) and 21 - 15(2) (which preclude adjustments for bad debts when accounting on a cash basis).