The following shall occur as action by Council:
   (a)   Within thirty days after the public hearing required by Section 1113.09 , Council shall, subject to Section 2.09 of the Charter, either adopt or deny the recommendation of the Planning Commission or adopt some modification of it, except in cases where subsection (b) hereof applies.
   (b)   Should Council determine that there is information or questions not considered by the Commission, it may return the issue to the Commission for reconsideration. The Commission shall meet and issue a recommendation to Council within thirty days of the return date. Within thirty days after Council receives the Commission's reconsidered recommendation, Council shall adopt, deny or modify the recommendation as provided in subsection (a) hereof. This return for reconsideration may be done one time only on a zoning amendment issue.