He certainly betrayed the trust and confidence of certain people and entities in the executive branch of the US government, that's not in dispute.
But it is morally obligatory to betray trust when you are trusted to do a thing which is itself morally indefensible. Whether Snowden betrayed a trust is not at issue, the moral (and, subordinate to that, legal) character of the subject matter of that trust is at issue.
But it is morally obligatory to betray trust when you are trusted to do a thing which is itself morally indefensible. Whether Snowden betrayed a trust is not at issue, the moral (and, subordinate to that, legal) character of the subject matter of that trust is at issue.