RCW 41.24.190: Proof of service.

The filing of reports of enrollment shall be prima facie evidence of the service of the participants therein listed for the year of such report as to service rendered subsequent to July 6, 1945. Proof of service of firefighters [participants] prior to that date shall be by documentary evidence, or such other evidence reduced to writing and sworn to under oath, as shall be submitted to the state board and certified by it as sufficient.