Dr. Jake Lambert signed an employment agreement with Baptist Health Services, Inc., to provide cardiothoracic surgery services to Baptist Memorial Hospital-North Mississippi, Inc., in Oxford, Mississippi. Complaints about Lambert's behavior arose almost immediately. He was evaluated by a team of doctors and psychologists, who diagnosed him as suffering from obsessive-compulsive personality disorder and concluded that he was unfit to practice medicine. Based on this conclusion, the hospital suspended his staff privileges. Citing the suspension, Baptist Health Services claimed that Lambert had breached his employment contract. What is Lambert's best defense to this claim? Explain.