Period. And here's why: Anytime someone screws up and even makes the tiniest attempt to try and shift the blame, it's tacky. It's poor sportsmanship. It's poor form. Since everyone is spouting analogies, here's mine: Let's say I throw you a can of Coke. You know, you're thirsty, and I go, "Here's a can of Coke," and I throw it to you. But you're not ready. You're not expecting that can of Coke to be flying across the room at you, and you miss it. You miss the catch, and you get conked on the head by my flying can of Coke. Now, if my response is, "Dude, I'm so sorry I hit you in the head with that can of Coke," that's appropriate. We'll probably remain friends, you and I. But, if I say something like, "Sorry I hit you on the head with that can of Coke, but you really should have caught it," well now, that's just plain old tacky. And you're probably going to remember that, and it will probably fester in your mind, perhaps for some years, until it finally comes out in some fit of rage that ultimately ends our friendship. 'Cause, basically, I'm an asshole for saying that, and I probably said a whole lot more stuff like that, and by now you probably have every reason to hate me. But I digress.
The point in time when you royally screw up — like Apple did by releasing iPods with viruses on them — is not ever a point in time when you want to be pointing out someone else's flaws. I don't know what it is about the social human mind that recoils at such behavior. It just does. And that's why most of us think Apple's response to their screw-up was just plain... Uh... Right, tacky!
Maybe they need to release another press release that says, "We're sorry we screwed up, and we're also sorry we tried to shift the blame." A-la, "I'm sorry I hit you with that Coke, and I'm sorry I tried to blame you for it after." That might help. Might.