You can sell your goods to a distributor for whatever price you and they agree on. What you cannot do is tell the distributor, or conspire with them about the price they will sell for. Dell is likely the one who helped get the legal proceedings started, if Hitachi was "black mailing" them, so to speak. Threatenting to halt shipments, break the deal, raise their price, etc. And companies this large once they start the purchasing process with a supplier, it is a lenghtly and very expensive procedure to simply "buy them somewhere else".
The legal version of this you see everyday, as "Manufacture's Suggested Retail Price" and everyone knows that you never pay this for a product.