Nope, you've got the wrong Kerr(e)y.
Adm. Zumwalt was in the Swift and PBR chain of command; he wasn't in the SEAL chain of command. His son (also retired Navy, a Captain I believe) is currently speaking on his behalf with the Swift boat veterans for truth group.
Zumwalt was Commander of Naval Forces in Vietnam from 68-70. Kerrey's platoon was part of Seal Team One, attached to Task Force 115 was part of Zumwalt's Command.