10.—(1) Subject to the provisions of this Article, the Department shall allow such disbursements claimed under Article 8 as appear to it to have been actually and reasonably incurred.
(2) No question as to the propriety of any step or act in relation to which prior authority has been obtained under this Order shall be raised on any determination of costs, unless the solicitor knew or ought reasonably to have known that the purpose for which the authority was given had failed or had become irrelevant or unnecessary before the costs were incurred.
(3) Where costs are reasonably incurred in accordance with and subject to the limit imposed by a prior authority given under this Order, no question shall be raised on any determination of costs as to the amount of the payment to be allowed for the step or act in relation to which the authority was given.
(4) Where costs are incurred in taking any steps or doing any act for which authority may be given under this Order, without such authority having been given or in excess of any fee so authorised, payment in respect of those costs may nevertheless be allowed on a determination of costs.