The procedures on a pretrial appeal to the Court of Appeals by the Commonwealth pursuant to subsections A and E of § 19.2-398, and on a cross appeal of a pretrial appeal by the accused pursuant to § 19.2-401, shall be governed by the provisions of subsections C and D of § 17.1-407. The Court of Appeals, however, shall grant or deny the petition for a pretrial appeal, and the petition for cross appeal, if any, not later than 30 days after the brief in opposition is timely filed or the time for such filing has expired. No petition for rehearing may be filed in any pretrial appeal pursuant to this chapter. If the petition for a pretrial appeal pursuant to this chapter is denied, the Court’s mandate shall immediately issue and the clerk of the Court of Appeals shall return the record forthwith to the clerk of the trial court.