Notwithstanding any other provision of law to the contrary, in order to facilitate the making of investigations by the director in the interest of public safety and promotion of aeronautics, the public interest requires, and it is therefore provided, that the reports of investigations or hearings or any part thereof shall not be admitted in evidence or used for any purpose in any suit, action, or proceeding growing out of any matter referred to in the investigation, hearing, or report thereof, except in case of criminal proceedings instituted on behalf of the department or of the state under this article and other laws of the state relating to aeronautics, nor shall the director or any officer or employee of the department be required to testify to any facts ascertained in, or information gained by reason of, his or her official capacity, or be required to testify as an expert witness in any suit, action, or proceeding involving any aircraft or air navigation facility. Subject to the foregoing provisions, the director may make available to appropriate federal and state agencies information and material developed in the course of hearings and investigations.