Whenever the manner of introduction of opinion or expert testimony is governed by requirements fixed under the provisions of WAC 446-08-470 or 446-08-490, such testimony not submitted in accordance with the relevant requirements shall not be received in evidence in the absence of a clear showing that the offering party had good cause for his or her failure to conform to such requirements.
Wash. Admin. Code § 446-08-500
Order II, § 446-08-500, filed 11/22/74.