Part 1 is a great start to the discussion about disagreeing with the boss. Although Mark touched on it in the podcast about the point of view of the manager, I wonder if there will be a Manager Tools podcast about "Dealing with direct disagreement?"
So far, Mark has stated to not disagree in a public forum with your boss. How would the situation be dealt with if the boss asks if there is any disagreement in the group at the end of a presentation or statement? In that respect, it seems like the boss is opening themselves up for public disagreement and perhaps putting their role in question. I have had a few bosses that have welcomed disagreement in group meetings. However they didn't start asking that until their role was well established and they knew their directs. Perhaps that is the trick.