(a) Upon the hearing of a writ of certiorari, the superior court may order the same to be dismissed or may return the same to the court from which it came with instructions.

(b) In all cases when the error complained of is an error in law which must finally govern the case, and the court is satisfied that there is no question of fact involved which makes it necessary to send the case back for a new hearing before the tribunal below, it shall be the duty of the judge of the superior court to make a final decision in the case without sending it back to the tribunal below.