It has a partisan interest in claiming this, but Labour-aligned blog The Standard says that Sir Roger Douglas didn't deliver the speech that was put out in his name, because it had been released early by mistake. According to the post, the Herald report on which I also based my own write-up was written only from Douglas's published remarks and a reporter did not attend the speech.
In the scheme of things, the slip-up doesn't really matter much. But if true, it does reflect somewhat poorly on the Herald as the report should have made this clear, especially since the report was accompanied by a photo of Douglas appearing to deliver a speech at the Rotary club. Was photographer Martin Sykes actually sent or was this a file picture? As for the speech itself, what did Douglas actually deliver and does his tax plan, as reported, stand?
UPDATE: I have found my own answers at the other end of the blogosphere.