Don't ever believe that you can't learn from someone who has stumbled at some point. Especially someone as distinguished as Colin Powell.

"stumbled" implies he wasnt aware when he did it. Not saying he was. Just pointing out the hidden assumption.

Hanlon's razor.

Doesn't mean he knows nothing about leadership. Dude got promoted to General on his merits.

Actually he got promoted for covering up war crimes in Vietnam.

I doubted your comment, then I looked it up, sure enough, according to Wikipedia Powell's handling of the assignment was later characterized by some observers as "whitewashing" the atrocities of My Lai.

http://en.wikipedia.org/wiki/My_Lai_massacre

Whether or not that was why he was promoted, I don't know. It may have had a part in it. From reading more, it seems like he's a Macnamara type who thinks some evil is done in the name of good.

That must be the experience that underlies Lesson 6 (no pun intended): "You don't know what you can get away with until you try".