If the last straw to leak this information was when Snowden learned about this MonsterMind program, why are we learning about it more than a year later without any prior mention whatsoever? (and without documents to back up the claims) Also, if he learned about it after taking up his job with Booz Allen Hamilton in 2013, why was he contacting Glenn Greenwald in December of 2012?[1] Ditto with the excuse that Clapper'…
I can understand the timing suspicions. Frankly, I'm in the camp that tends to trust Snowden, but putting that aside, I think some discrepancies could at least be partially explained by one or more factors:
a) the journalist is putting some words in Snowden's mouth about "last straw" or "the time had come to act";
b) Snowden was still deciding what actions to take (yeah, he emailed Greenwald back then and was almost certainly going to share something, but may have been on the fence about how far to go);
c) Snowden has sort of unconsciously mentally revised the exact timeline -- I think this is not unusual for someone looking back on their "life-changing moments", difficult decisions, months-long transformations etc. Or, the quote about Clapper may have been Snowden using it as a microcosm for everything else that put him down the path he was already on (by contacting Greenwald.) Maybe as it happened he saw it as vindication of the decision he'd already made. Maybe he was going back and forth for months -- although he'd contacted Greenwald and started collecting documents, he had left open the option of turning back, but had his resolve renewed by "the Clapper event."
So yeah, it's fishy, but I don't think there are any smoking guns per se. It's not like they quote Snowden as saying, "After Clapper's false testimony, I contacted Greenwald for the first time" while Greenwald says it happened 6 months before.
Pro-NSA people say it's not a fair debate because the government isn't allowed to talk about the classified details. That applies to Snowden too, because it's difficult for him to communicate his side to the public, being filtered through journalists (who may be juggling his quotes around and mixing up the timeline for the sake of a better story) and not having many opportunities (or eschewing them, to avoid becoming the center of focus.)
I read an interesting and new (to me) statement of intense premeditation in "There was one key area that remained out of his reach: the NSA’s aggressive cyberwarfare activity around the world. To get access to that last cache of secrets, Snowden landed a job as an infrastructure analyst with another giant NSA contractor, Booz Allen." So he took a job specifically for the access it would afford him, with the specific intent to steal and leak?