Any officer or director of a domestic insurance company who makes or authorizes an investment or loan in violation of section 26.1-05-19 or 26.1-05-20 is liable personally to the stockholders of a stock insurance company, or to the policyholders of a mutual insurance company, for any loss occasioned thereby. If a company is under liability for losses equal to its net assets and the president or directors, knowing of the liability, make or assent to further insurance, they are liable personally for any loss under the insurance. If the directors allow to be insured on a single risk a larger sum than that permitted under section 26.1-03-01, they are liable for any loss thereon above the amount the company might insure lawfully, unless the excess is reinsured as required by that section.