The evidence in any investigation, inquiry, or hearing may be taken by the member to whom the investigation, inquiry, or hearing has been assigned or, in his or their behalf, by an examiner designated for that purpose. Every finding, opinion, and order made by a member so designated, pursuant to investigation, inquiry, or hearing, when approved or confirmed by the board and ordered filed in its office at the State Capitol, Sacramento, is the finding, opinion, and order of the board.