It is illegal - very, very, very illegal - for a soldier to engage in negotiations with the enemy unless he has been given express permission to do so by superior officers (superior as in damn near the very top of the chain of command). I don't know if this would count as actual treason, but if not it's extremely close.
Beyond the violations of military law, there's also the possibility that what he did may have changed the course of the war in favor of the Communists, and made things much worse for POWs still being held by the Vietnamese at the time.
As for how the media should handle it, I just hope they wait till Friday. A home-run Bush speech Thursday night followed by immediate charges of treasonous activity by Kerry on Friday morning could be a one-two knockout punch that will destroy the Kerry candidacy.
Think of the new refrain throughout the party - including McCain: "What he did during the war is noble. What he did after his return is fair game for attack."
If this is true, thinking back now at how hard McCain came out against the medal stuff and specifically endorsed the post-war stuff, well...it is a thing of beauty. It is a perfect set-up to get the swing voters on board for post-vietnam era charges.
Of course, that's just my wishful thinking of how it'll play out. And, it doesn't seem we'll need it after this week (icing on the cake).
Now THAT could be the smoking gun: John Kerry in Paris, and quotes from his "negotiations" winding up as documented propaganda used against our POWs.