All Disney have done from their "you can't prove anything else" point of view is cut costs by finding a cheaper source of local labour through a 3rd party. They have no control over how said 3rd party arranges for the cheaper labour to be made available, or at least no control that can be proven beyond doubt. In fact they probably have no interest at all in how the people get to them - it is none of their business and something to concern the 3rd party only. At least that is my reading of the situation.