I've never liked anti-virus companies - not just because they sell stuff that doesn't address the root cause of the Windows problem, but mostly because sometimes they seem to go out of their way to ensure people are aware that viruses can exist for any platform, just in the off-chance they can charge you for "protecting" it.
Remember, folks, these are the people who warned you about Pocket PC viruses (which, by the way, are almost as thin on the ground as Mac ones). And about Symbian viruses (or the likelyhood thereof, since all that ever popped up were a couple of stunted trojans you had to be pretty clueless to run anyway). These are the people who search so avidly for new markets that they who tried to sell you 2MB of executable code to protect your Palm from Windows viruses.
In short, the people who have waking, hallucinogenic dreams regarding all forms of unfeasible contagion by propagation of executable core across just about every computing platform known to man (except for the toaster), without the aid of recreational chemicals (although they obviously need the smell of fresh dollar bills to keep high).
So it doesn't surprise me in the least that one of the flagship companies in that market completely botched up the "announcement" of a Mac virus - or something that is nothing more than yet another proof of concept without any real risk whatsoever.