Note that the real world operates like this too: before computers, if someone changes their address and simultaneously sends a package, the package probably will end up at the wrong address. We have a number of mechanisms in place to mitigate this when it occurs (address forwarding, return-to-sender, customer support, credit card chargebacks), but they
still don't always work, and sometimes packages just get lost.
The real world solution to this is the acceptance that yes, sometimes bad things happen for no reason at all. I suspect that the computer world will eventually move to this as well, with consumers becoming more tolerant of machines that simply give the wrong answer some of the time, as long as they give the wrong answer less frequently as a human would.
