1) the information had already been published.

2) wildly speculative and wildly inconsistent with all of Greenwald's other behavior.

3) I imagine you have some kind of conspiracy theory to justify this one?

In this case, the simplest answer is that a dead man's switch gives Snowden a bit of additional leverage, and that Greenwald mentioned it to help the reporter interviewing him understand the dynamics of the situation.

Next time read the article you're commenting on.

I did read it. Did I miss something that invalidates my counter argument?

Yes.

and what was it?

Read the article, then reread your comments. You're plenty smart, and it's pretty obvious.

I just re-read it a third time and do not see what you're referring to. If you'll humor me and paste in the relevant paragraph I'll give it extra attention and (I hope) admit if I was wrong above.