If the City Council proposes to alter a proposed zoning amendment recommended by the Planning Commission, or to alter or adopt an amendment which has been denied by the Planning Commission, or to alter a proposed zoning amendment for which Planning Commission review is not required in accordance with section 25.010, the City Council, in its sole discretion, may either: refer the proposed altered amendment back to the Planning Commission for report and recommendation before adoption, or adopt the proposed altered amendment. Failure of the Planning Commission to report to the City Council within thirty (30) days of the City Council’s referral shall be deemed approval by the Planning Commission of the proposed amendment.