No, you don't. And my suggestion was a fail-safe one. Realistically, he should 1) Demand a refund, then 2) See apple's policies about refunds and complain through them, then 3) See if his credit card allows chargebacks through "buyer's remorse" and if not, 4) Say you didn't buy it.
Obviously, this guy made a mistaken purchase, and if it was a physical store it would never have happened.
Regardless, the way that the Apple store tricked his muscle memory by not having a confirmation page borders on fraudulent. If they would not reverse this honest mistake when you present the situation to them, then I would have no problem perusing this by other means.
Why is no one paying attention to this?
I, too, think this app sucks... but "caveat emptor" doesn't still apply?
Check out Kottke (who I also am not especially fond of) for a reality check on why it's not apple's place to remove the app...
If you clicked on a link that says "Buy Now" and for whatever reason it ran your card on file and you didn't expect it to then that is good enough reason to get a refund from the merchant and if not from the merchant then put in a dispute.