Except that the total amount of proof of anything Manning has done at the moment, is ZERO.
You mean, except for the thing about him pleading guilty to charges? You know, described in that thing at the top of this page we call a summary?
You've never been charged with a crime by the government, have you?
Lemme drop a little free-range wisdom on ya: The justice system is fucked. Often times, accused people are given 2 choices by prosecutors: plead guilty and get a lesser sentence, or fight to prove your innocence (yes, that's right, it's no longer 'innocent until proven guilty') and risk having the book thrown at you. It doesn't matter whether you're actually guilty or not, it's all just a farce to keep the money flowing through.
Don't take my word for it, go steal a candy bar from Walmart* and enjoy the anal-raping courtesy of the US corporate court system.
* Wal-mart always prosecutes. Always.
That's by design, actually. The prosecutor, if he believes you are guilty, attempts to bring the full force of the law down upon you; if you are innocent, then the concept, at least, is that the truth will out (given that you only need reasonable doubt to escape punishment). Due to economic realities, however, we can't afford the costs of a full trial, so in cases where the defendant knows he is guilty and is likely to face the full punishment for his crime, he is given a chance to reduce his punishment and the economic burden on the taxpayers.
If you're innocent, man up and say so. If you're guilty, plea. Don't give me this "I only commited purgery and plead guilty because I thought they were going to find me guilty anyway" crap. We have a justice system to respect your rights, but if you don't use it, it's your own fault.