I think he might have had a few more people on his side if he would have said this from day one.
Maybe he anticipated how they would try to play the game?
Snowden: I have docs showing
NSA: no you don't
Snowden: here they are
NSA: ok, but you should've worked within the system
Snowden: I told 10 people in the system
<--- where we are today
NSA: no you didn't
Snowden: here's who I told and when
NSA: ok, but <another attempt to change the focus to Snowden...>