Del. Code tit. 18, § 5109

The Commissioner may make such rules and regulations as may be necessary for the execution of the functions vested in the Commissioner by this chapter and may for such purpose classify domestic stock insurers, securities and other persons or matters within the Commissioner’s jurisdiction. No provision of §§ 5103, 5104 and 5105 of this title imposing any liability shall apply to any act done or omitted in good faith in conformity with any rule or regulation of the Commissioner, notwithstanding that such rule or regulation may, after such act or omission, be amended or rescinded or determined by judicial or other authority to be invalid for any reason.