(1) Notwithstanding the provisions of section 33-514, 33-1271 or 33-1273, Idaho Code, school districts may employ school resource officers, certificated schoolteachers, and administrators who are receiving retirement benefits from the public employee retirement system of Idaho, except those who received benefits under the early retirement program previously provided by the state in positions requiring such certification, as at-will employees. Any employment contract between the retiree and the school district shall be separate and apart from the collective bargaining agreement of the school district.