Discrimination-based litigation is the wrong approach in this case. As I predicted earlier, federal courts usually do not second-guess licensing/certification authorities' decisions. It’s like asking the court to issue an order to issue bar licenses to practice law without passing the bar exam. Not likely to happen. USMLE and related qualifications/residency are there to establish someone has the skill and knowledge to practice medicine in the US, and this is a national security and public safety issue. The best way is to sue the NBME on an individual basis and make them produce evidence they have on you showing that you have cheated. Then you can lay out your counterarguments and possibly be allowed to retake the exam and get similar results, proving that you indeed got your scores fair and square. This is a high bar and is going to be really difficult to have your score restored.