(a) All hearings, investigations, and proceedings shall be governed by this part and by rules of practice and procedure adopted by the commission, and in the conduct thereof the technical rules of evidence need not be applied. No informality in any hearing, investigation, or proceeding or in the manner of taking testimony shall invalidate any order, decision or rule made, approved, or confirmed by the commission.
(b) Notwithstanding Section 11425.10 of the Government Code, Chapter 4.5 (commencing with Section 11400) of Part 1 of Division 3 of Title 2 of the Government Code does not apply to a hearing by the commission under this code.