Jon had remembered that the stone, while it had limits, also let the user reinterpret the wishes. This interpretation was easy, since Chad had pretty much said it--all he had to do was be specific enough that the stone wouldn't mess it up. "I wish that Chad will turn into the girl Julie."
It was the correct fix; at least it seemed to be. The second dog transformed and grew in just a split second into the form of a person. Julie.
"Okay, Chad, reverse the wish," said Jon.
"Chad?" she said, confused. "I don't remember making any wish."
"Chad, your dog Julie. The one who was your girlfriend. You know, the one you told me about, who looked like you do now?"
"Why would I make a wish on my dog?"
"Wait a minute, Chad. What's the last thing you remember?"
"Why are you calling me Chad?"
"Because before you turned into Julie, you..."
"I didn't 'turn into Julie'. Jon, it's always been my name!"
It occurred to Jon that dogs can't understand human speech. Chad hadn't heard the wish that changed him into Julie. So as far as he was concerned, he really was Julie. Maybe the wish really did work as intended, and he could reverse wishes that Julie had made, but he didn't even know about them now.