Yes, he did.
The media is getting confused, but in this case, it's understandable.
Air Chief Marshal Angus Houston, the retired Royal Australian Air Force officer (and former Chief of the Australian Defence Force - ACM is a four star rank) gave a press briefing only a very short period of time after Prime Minister Tony Abbott had made a statement to the press. ACM Houston was talking about one set of signals picked up the previous night now being considered a mistake, and that media reports about them were therefore incorrect. He did not know the Prime Minister had made a new statement only a couple of minutes earlier, so he was not talking about that statement being incorrect.
They seem to have spoken to the press less than two minutes apart from each other.
Confusion on MH370 after conflicting reports on black boxes from Tony Abbott and Angus Houston outlines what happened in more detail.
Thanks.
Excellent update.
Of course, that has no bearing on where MH370 is now, but it could have a lot to do with why it is where it is.