Columbia University fired a mesothelioma research expert who was a central prosecution witness in the criminal case against New York state’s former Assembly speaker without following the school’s own termination procedures for tenured faculty, a judge ruled.

Manhattan Supreme Court Justice Manuel Mendez affirmed the findings of a special referee who determined the college violated Dr. Robert Taub’s due-process rights by terminating him in 2015 after federal official corruption charges against former speaker Sheldon Silver came to light.