He didn't follow whistleblower procedure and fled to an adversary. If he believes he is being noble then he should stand trial in good faith. Best case he wins and gets off, worst case he does jail and is proven right.
https://www.pogo.org/analysis/2016/09/busting-myth-of-whistl...
The espionage act under which he'd be charged doesn't allow a public good defense to be used in court.
https://www.justiceinitiative.org/voices/why-snowden-won-t-g...
What you're asking for structurally can't happen in the US legal system.
I just really don't like fleeing. Now that he fled he is fucked and looks guilty.
You keep saying you "don't like fleeing", but you haven't provided an alternative that would both provide real change and not have him being threatened with the prospect of a firing squad.
So no - he didn't "flee to an adversary", as much as he was "forced to stay at advesary's".
PS: US "justice" system would have granted him no justice. So you can stick that "good faith" argument in the same location where I tell people to stick their "go march in Pakistan with your PRIDE flag" arguments.
Edit: What a surprise, you "work in defense".