28. Where, in relation to an existing appeal—

(a) a hearing has commenced but is not completed before the commencement date, or

(b) a hearing has been completed but a determination has not been made before that date,

by the one or more Appeal Commissioners who presided over the hearing (and the omission to complete or do the foregoing thing is due to those Appeal Commissioners having vacated, in whatever circumstances, office), the appeal shall, as one or more other Appeal Commissioners decide, either—

(i) be reheard by the latter Appeal Commissioners as if the first hearing had not taken place, or

(ii) instead of being reheard, be adjudicated on and determined, subject to subsection (3) of that section, in accordance with section 949U of the Act of 1997,

and, following the taking of such steps, the provisions otherwise of Part 40A shall apply accordingly.