So to claim that WikiLeaks would fixup all of Snowden's writings to conform to en_GB and then switch it right back to en_US after HN notices is rather surreal.

At best you could claim that Harrison herself simply transcribed Snowden's speech and that no one caught it until it was posted. But that still wouldn't explain what happened to some of the missing words that Snowden would have said. And that still wouldn't explain why WikiLeaks revised a statement so important without so much as a mention of proofreading corrections post-facto.

I think you need to loosen your tinfoil.

Does that sound like the same person talking about civil liberties and how Obama didn't change enough for him, and being ready to stand up for what he believes in? Or does that sound more like a certain other ego at opposition to the U.S. government and especially its President?

The concern would be if wikileaks were completely fabricating this, but I see no evidence for that. (Nor any motivation.)

I doubt they are fabricating it, but honestly they have Snowden in as much of a bind as the U.S. does now. They are his only source of support right now... what does he do if they take it away? He's in a web of very unequal relationships right now.

This assumes he has other channels of communication. He probably stands behind it insofar as its consistent with everything I've heard from him so far, but neither of us has any way of knowing for the time being.

If you want to preserve your credibility, it's better to either leave the mistakes in, or explain the context (eg 'this statement was a written record of a verbal statement; we apologize for an inaccuracy in our transcription of Mr. Snowden's recorded words').