Jon is helpless

Or he would have had the stone had he not been too distracted checking out his new body to hold onto it. As soon as the change was made though Sarah/Morganna in Jon's body grabbed from the limp hand of her old body depriving Jon of it. "Hey, give that back!" Jon cried from within in Sarah's goth body. "You've had your fun. Let me switch us back." Sarah however refused "No, I'm gonna keep it for a while. See if I can loosen this town up a bit. You got a problem with that?" Jon of course did, but he was quite certain he couldn't just say so at the moment. There was no telling what Sarah might do to him. For now he had to just play along. "No, go right ahead" He told her and waited to see what she would do next.