DURHAM — A former Duke lacrosse player has filed a civil suit against Duke University and a professor, charging that the teacher unfairly gave him a failing grade after an escort service dancer said she was raped at a lacrosse team party. An attorney for Kyle Dowd, who graduated from Duke last year, filed suit in Durham Superior Court on Thursday. Dowd and his parents, Patricia and Benjamin Dowd, are suing Duke and Kim Curtis, who is listed on Duke’s Web site as a visiting assistant professor in political science. Curtis, who specializes in political and feminist theory, would not...