While you are still subject to the UCMJ and still in the military you are forbidden from the kind of speaking that he did. From wearing the uniform in an indignant manner as he did, from collaboration with the enemy (which you can't do as a civilian either)
He might not be formally charged, but then again he may. What if the Dems are hoping that he does get elected, then let the charges fly since they really want Edwards as president. They new he was too young and too new to get elected on his own merits. So they help Kerry get elected, then impeach him for treason and convict him of same. Then edwards becomes president.