I guess it is ok to say that Kerry lied and is unfit to be CIC, as the initial ad said. You just can't say that he betrayed his comrades and country. The distinction is lost on me in terms of libel law.
treason (fromWebsters ll New Riverside Dictionary)
1. Violation of allegiance toward one's country or sovereign, esp. the betrayal of one's own country by waging war against it or by consciously and purposely acting to aid its enemies.
2. A betrayal of trust or confidence.
If the shoe fits.....