I would like to write a story about the out of court dispute resolution which happened in my company. It would give an idea what mistakes and negotiation can be used in similar cases. So, my company is electromechanical supplier for the US army and many times we make very specific assembly. In this case the estimation was done for the whole BOM. During the purchasing one of the coworkers lost number 2 in the part number for the long cable. The vendor also had similar part without the 2 and that what they sent. The difference was that they sent same cable just much shorter. The part was non-returnable and the purchase was final ($10,000). President of the company wanted to return it and they decided that they will accept it for 50% of the price. So my company sent them the letter that they can agree on 25% loss, since the mistake was on both sides. The estimation was done for the right part and the purchase was done for the wrong one. Of course even that we received the short cable we paid as for the long one. After sending them the letter with all the facts they agreed to take only 25%. So, in my opinion if you can present good documentation supporting your case you can win out of court dispute resolution.