why does nurse ratched finally get mad at mcmurphy

McMurphy follows Nurse Ratched into the Nurses’ Station, smashes through the glass door, and attacks Nurse Ratched. She is terrified; she knows he will kill her, and this she will never forget. He tears the front of her uniform off, exposing her breasts; this he does to humiliate her and address the issue of her sexuality which the men she rebukes. Here, McMurphy attacks her deepest weakness. With the other powerful hand, he starts to strangle her, with no regard for his own safety or punishment. The patients don’t stop him; they feel they can’t stop him and simultaneously know that they want him to do it, and he is obeying them. The aides, selfish and wrathful, don’t try to stop McMurphy; they fear him as Nurse Ratched does now. They show their lack of redeeming qualities as they only serve their own sadistic ends. Finally, other doctors and nurses pull McMurphy off Nurse Ratched, and he screams a scream of total defiance, knowing he has lost, but remaining defiant to the very, very last.