Karyn knew, Jon had made a wish to wear the clothing identical to Karyn, as some type of curiosity. Karyn was confused about how that could be, wasn't he dressing like this for her assignment? The stone never lied to them so far, so she knew it was giving her the truth. It showed her the actual event, where he made the wish. Since it was made away from her, she never knew it. Therefore, she did not notice the effects of it.
She felt very unsure on this, and then . . .
