Not Dead Dad

"You know, since Dad died a long time ago, I wonder how we're living now. Are we just living alone without any parents?" Jon asked. Suddenly, there was a knock on the door and when Jon opened it, he discovered that it was his *dad*. But how could that be? He was supposed to be *dead*. Did his mom accidentally make any other wishes? Or was this a side-effect of the wish that made Jon's mom his sister?