It's standard operating procedure with the White House, no matter who is President, to try to discredit opponents. This is the core of the Plame affair - calls to friendly journalists to plant stories in the press, revealing classified information that suits their purpose.
I don't believe we can trust the NSA's comment regarding "the only communication from Snowden it[NSA] could find". I highly doubt if they found evidence to support Snowden bringing up issues internally, that they would release that information.