He provided neither help nor comfort to the enemy. Please get your facts and sources right.
He witnessed an American helicopter shooting civilians including two children and two journalists.
Knowing that the pilot never got fined for what he did, and therefore having a guilty conscience for working in the army when the army didn't seem to be doing what it promised its people, he released the documents and facts for the rest of the people to see. In other words, he put the truth out there.
The real question is, if it was a fair shoot, why would the American government hide this and other videos and documents from the public???!!
His deed is not helping the enemy, but showing some truth to people, including American people. So, I suppose that's helping Americans. (TRUTH WILL SET YOU FREE!!)
The government does not like that since these released documents can decrease their popularity among their own nation, and possibly the world.
To me, that is just shooting the messenger...literally!!
See this video COMPLETELY until the end, then judge: