Well, remember that Ryan's social worker, at least the one he had in Chino, was an idiot who regarded Ryan as a liar and criminal. He may have it in his files that Ryan ran away from home (especially since Ryan never put himself on the radar after Dawn kicked him out...), and there's nothing, except Ryan's word, to prove that Dawn abandoned Ryan instead of him running away... plus,it says in the story: 'the neccesary money to be offered'... Caleb's not above a few bribes to make sure that what he deems as a bad influence and possible danger to his family is far away from them...