(a) The authority may revoke the prequalified status of a contractor on the basis of either changed circumstances or discovery of new evidence that indicates the firm does not meet the authority's standards. Following such revocation, the authority shall determine the appropriate period of disqualification in accordance with the standards enumerated in section 9600.3 of this Part. If it is determined that the contractor knowingly and willfully submitted a false instrument for the purpose of defrauding the authority or of obstructing an official investigation, the authority may revoke the contractor's prequalification status permanently.