Rich Rodriguez is firing back at his ex-assistant accusing him of sexual harassment -- saying her claim he grabbed his wiener in front of her is such complete bullcrap, he took a lie detector test to prove it. It's all outlined in RichRod's attorneys' response to Melissa Wilhelmsen's notice of claim filed with the AZ Attorney General's office ... where they denounce the allegations that the ex-University of Arizona football coach terrorized her for years. In the 290-page document, Rodriguez's lawyers poke holes in Melissa's most serious accusations -- including the "shameless, outrageous lie" that RichRod began "grasping his penis beneath his basketball shorts" in a closed-door meeting. His lawyers say Rodriguez took a "rigorous polygraph examination" administered by a member of the American Polygraph Association to fight this claim -- and the results prove their client's innocence.