In other words, the host audio is "on mic" and the guest audio is "off mic" and only audible from the hosts mic. After much head scratching and whatnot including loading the card back into the camera, playing the clip back and monitoring through earphones with the audio sounding correct, I took the P2 card into one of our News edit bays (Edius) and imported the clip and the host audio is on channel 1 and the guest audio is on channel 2.
Came back to FCPX, created a new library, loaded up card, and at the import screen, selected and played the clip and can only hear the host audio. Went ahead and reimported the clip into the new Library, created a new project, dropped the clip into the timeline . . . can only hear the host audio from channel 1.