This might sound rough but the lesson should be "don't be an idiot".

Time for shouting "king's naked!" comes eventually but people who ignore timing will end up losing this game. The secret to this is to understand how other decision-makers see the status quo. Who made a bet on this person? Who understands that he is THE problem? Is right now the best time for a direct opposition?

And sometimes it's just easier to accept that it may make sense to work elsewhere.