Can a police officer testify as to the contents of a telephone conversation that was intercepted without the consent of both parties?

The Washington privacy statute requires the consent of both parties or a warrant in order to record a confidential communication and provides "[a]ny information obtained in violation [of the privacy act] ... shall be inadmissible...." (RCW 9.73.050.) In State v. Grant (1973) 9 Wash.App. 260, 511 P.2d 1013, an appellate court ruled the Washington act did not preclude a police officer, who had not been party to an aural interception which was legal under federal law but improper under state law, from testifying as to the contents of the recorded telephone conversation.