Notwithstanding Section 22132, if a person who begins to receive a disability allowance under this part after June 30, 1972, is employed, or is self-employed in any capacity in which his or her average earnings for any prior continuous six months amount to 66 23 percent of the indexed final compensation, the person shall be presumed capable of performing gainful employment and no longer disabled. The disability allowance shall be terminated on the first day of the month following the six-month period. Any allowance paid thereafter shall be considered an overpayment and recovery shall be made.