But don't you find it the least bit strange that Duffy didn't say that tests are ongoing, or refused to comment on it? In the previous times when Zarqawi was reportedly killed, I don't recall the White House saying that it was very unlikely to be true. It seems like the White House is trying to lower expectations. Which is what you want if Zarqawi was in fact killed, because you want to see if his other associates try to contact him, before you announce his death.
Let me just say that that White House spokespeople deceive the American people frequently. I'm taking this more as spin than a real evaluation of the situation in Mosul.