I can't speak for the whole brigade, but I find the lack of technical evidence suspicious. And I don't limit myself to technical evidence I get to see, but when FBI doesn't get access to the servers I find that suspicious, even though I wouldn't have access to their findings until it had been used in legal proceedings.

Since we have general surveillance on the Internet, NSA should have a decent amount of evidence, proving at least that there was an intrusion and a copying of emails. If NSA published findings that Snowden and VIPS accepts as evidence, I would tentatively accept it. Still possible that it is forged evidence of course, but forgeries bring their own risks of exposure down the line.

And while my general trust in Assange is pretty low, Wikileaks has so far held a high standard in what they publish, and from what I've seen of Craig Murray (who is supposed to have received at least the DNC leak), he appears trustworthy enough.

So for now, I think leak is more likely than hack.