Neither the ombuds nor the ombuds's staff may be compelled, in any judicial or administrative proceeding, to testify or to produce evidence regarding the exercise of the official duties of the ombuds or of the ombuds's staff. All related memoranda, work product, notes, and case files of the ombuds's office are confidential, are not subject to discovery, judicial or administrative subpoena, or other method of legal compulsion, and are not admissible in evidence in a judicial or administrative proceeding. This section shall not apply to the oversight board for children, youth, and families.