RCW 15.66.220: Compliance with chapter a defense in any action.

In any civil or criminal action or proceeding for violation of any rule of [or] statutory or common law against monopolies or combinations in restraint of trade, proof that the act complained of was done in compliance with the provisions of this chapter or a marketing order issued under this chapter, and in furtherance of the purposes and provisions of this chapter, shall be a complete defense to such action or proceeding.