I suspect the "second NSA leaker" is just Jacob Appelbaum with the same set of documents that Laura Poitras brought back to Der Spiegel. There's already several people in the infosec community doubting the veracity of some aspects of the Tor article[1][2][3], including from within the Tor developer community itself[4]. Though there's no confirmation, some have suspected that Julian Assange's most likely source for the Afghanistan revelation back in May[5] was Appelbaum[6].

[1] http://blog.erratasec.com/2014/07/validating-xkeyscore-code....

[2] https://twitter.com/thegrugq/status/485158875721523200

[3] https://twitter.com/electrospaces/status/485193336912093185 (scroll up)

[4] https://lists.torproject.org/pipermail/tor-dev/2014-July/007...

[5] http://gawker.com/why-did-wikileaks-name-country-x-when-glen...

[6] http://www.csmonitor.com/World/Security-Watch/Backchannels/2...