A director of an insurer is deemed to have such knowledge of its affairs as to enable him to determine whether any act, proceeding, or omission of its directors is a violation of any provision of this chapter. If present at a meeting of directors at which any act, proceeding, or omission of its directors which is a violation of any such provision occurs, he must be deemed to have concurred therein unless at the time he causes or in writing requires his dissent therefrom to be entered on the minutes of the directors. If absent from such meeting, he must be deemed to have concurred in any such violation if the facts constituting such violation appear on the records or minutes of the proceedings of the board of directors, and he remains a director of the insurer for six months thereafter without causing or in writing requiring his dissent from such violation to be entered upon such record or minutes.