Here is a more detailed account of Montgomery.
http://www.reviewjournal.com/news/nevada-companys-troubles-entangle-gibbons-federal-government
It appears he didn’t work for the government after 2004/2005. Any information on his hard drives would be from before that time.
Not necessarily...in the KJZZ article, Montgomery maintains his data was "copied from the CIA" not that he obtained it while he was an employee of the CIA. (I don't think that is an insignificant distinction)
It doesn't seem impossible to me that he would either still have a backdoor in (improbable, but the CIA hasn't covered itself with glory in some aspects of IT related things) or he could have obtained it from a willing leaker (we KNOW there are those as well).
Just trying to keep an open mind on this stuff.