no a mule is suppose to be any coin that doesn't have the matching dies (not saying double head or tail). That's to say any coin that if the coin has the wrong image on that design it's said to be a mule. In this case it cause in 1988 all even proofs, were suppose to be of the "Commemorating the Australian Bicentenary" design so that a Coat of Arms (normal coin) becomes a mule design as it wasn't suppose to happen that year nor does the mint make any mention of this.