[jjoonathan]

Why did you leave out the quote immediately after that? It's relevant.

> the Australian agency "has been able to continue to cover the talks, providing highly useful intelligence for interested US customers"

Whey would they say that the (continued!) intelligence provided by the Australian agency was "highly useful" if their counsel ruled they couldn't use it?

[codex]

Because there was other intelligence to be gleaned which was not the result of spying on Americans. Only the law firm was American; the rest of the parties were not. It's possible (likely?) that the NSA said, "give us everything with a non-American source" which would keep them within the law. I have not seen any evidence from Snowden that the NSA deliberately breaks the laws that bind them, though they make give the law liberal interpretations at times.