What happens with Mr. Harding at the therapy meeting?

In Part I, Chapter V, Harding defends Nurse Ratched against McMurphy's accisations and claims that she is a strict middle-aged lady, but no monster. McMurphy replies that she has him by the balls. Harding claims that she is a “veritable angel of mercy” who is “unselfish as the wind”—but Harding finally relents and admits that McMurphy is right, only no one has actually said so before.