A nearly decade-old negligence lawsuit involving sex at a high school can continue through discovery after a state appellate court told an employee to disclose his investigation notes.The 1st District Appellate Court opinion rejected the idea that Daniel Cates, who was then Hoffman Estates High School’s special education director, could conceal about 100 pages of notes — which were taken over two years after the school learned about sexual conduct on its premises — because they were protected by attorney …