Except an allotment for an unearned insurance premium, an allotment paid from the pay and allowances of an employee for the period he is in a missing status may not be collected from the allottee as an overpayment when payment was caused by delay in receiving evidence of death. An allotment paid for a period after the end, under this subchapter or otherwise, of entitlement to pay and allowances may not be collected from the allottee or charged against the pay of a deceased employee when payment was caused by delay in receiving evidence of death.