Commission's determination of necessity as evidence.

In such action the commission's determination of the necessity of the investigation, valuation, appraisal or services shall be conclusive evidence of such necessity, and its findings and determination of facts expressed in bills rendered pursuant to RCW 81.20.020 through 81.20.060 or in any proceedings determinative of such bills shall be prima facie evidence of such facts.[ 1961 c 14 s 81.20.040. Prior: 1939 c 203 s 2(c); RRS s 10458-6a(c).]