I find the ending of Sideways much more effective than Monster's Ball. Regardless, I enjoyed your defense very much.
You mentioned that we know what will happen to Jack, but I think this is a point where I differ with you. I, personally, felt that there was ambiguity in his character. The fact that he is an actor clouds the truth to everything he says. I think most people take his confessions to Miles as being false, but I'm not so sure.