There's evidence[0] of other, possibly currently active, whistleblowers leaking documents from inside NSA. This database includes those leaked documents as well, as it mentions XKEYSCORE, which Snowden has said he did not leak.
He had access to the NSA servers even after he fled using credentials from other employees.
Sorry I can't find a citation but I read about it about 6 months after the initial leak.
What was the name of this doc? There is some date incongruity here, unless Ed got his old job back.