Three statements separating poor and great leaders

Many people think they are great, but when push comes to shove, they succumb to fear - and avoid doing the very thing that would be required for others to move forward. This applies to workers and managers alike - it's everyday leadership that we should all exhibit, or, as Tobias Mayer coined the term - it's merely "thoughtful citizenship".
Here are three statements that many leaders might be too afraid to state:

I don't know

Smart people can easily come up with a plan or explanation which sounds so feasible that others will nod in appreciation. People with high charisma can make others believe even the most ludicrous things, such as for example: "clouds are actually giant, floating marshmallows".
This is very dangerous, as there is a huge potential of leading people on rabbit chases, and in extreme cases - even on witch hunts against those who disagree. The more respect a person receives, the more ready they should be able to state, "I don't know". Prominent leaders exercise great caution when making claims or providing instructions, as they have experience that a statement affecting many people can lead to massive problems, even when made from the best intentions.

I was wrong

"Hindsight 20/20". It's easy to be wise after the event. Statements about the future are always subject to error. Great leaders know this, and when they discover a dead end, they should be the first to pronounce, "I was wrong, we can't go on like this." Similarly, when they haven't seen the problem by themselves and are made aware by others, the three words will be like a rain of relief after a scorching summer: "I was wrong." - no lingering, no justification. Just closure. This open the door to progress. It frees others to go on.

I need help

Many people feel that exposing vulnerability is a sign of weakness, something that can and will be used against them. Great leaders don't care about weakness as much as about strength. Instead of saying, "I can't do this" - they say, "I need your help to do this!", knowing full well that everybody is good at something else.

In some cases, they will even ask others from help not because of their own need - they do this in order for them to grow and build them up! 

Summary

"I was wrong." - "I don't know" - "I need your help." 

These three sentences sound like they describe a weak person, even though saying these three things requires an incredible amount of courage. A person using these three sentences when appropriate displays massive strength of character and integrity. On the other hand, a person too afraid to speak these simple words when needed isn't worth following.

Do you have the courage to stand in front of your team, your company - even your own family - and say these words?

What consequences do you expect when you utter them?