If after a hearing and certification by the department of transportation the director of the department of insurance and financial institutions finds that an insurer has failed to comply with section 28-4148, the director of the department of insurance and financial institutions shall impose a civil penalty for each violation of not more than $250 per day for each day the insurer is in violation of section 28-4148. The director of the department of insurance and financial institutions also may suspend the insurer’s certificate of authority until the insurer complies with section 28-4148. No penalty shall be imposed pursuant to this section if noncompliance is determined by the director of the department of insurance and financial institutions to have been inadvertent or accidental. The burden of proving that the noncompliance was inadvertent or accidental shall be on the insurer.