Passionate dispassion
Someone who is actively involved in, or is managing, an activity is patently not independent of it. They may well make a conscious, rational and determined effort to be objective, dispassionately reviewing evidence etc ., but their subconscious/emotional biases/prejudices and beliefs/value-systems will inevitably influence what they do. With the best will in the world, they will struggle to challenge and assess their past decisions and activities, especially if they were "certain" or "determined" or genuinely believed they were "doing the right thing". Furthermore, it is very hard for anyone to review the things they did not do, decisions they did not make or options they did not even consider. Mostly, they remain out of sight or out of the question.