Last modified: 2008-08-30 17:00:45 UTC
In the screenshot linked, some edits on the article http://de.wikipedia.org/wiki/Investition have an exclamation mark, some don't. None of the revisions in the screenshot is flagged.
When someone sights an edit, the previous ones have the flags removed. However when an edit, or group of edits, is rolled back, those edits have there marks removed (this is done by the core software).