While listening to episode 124 of the Cranky Geeks Podcast with John C. Dvorak, the topic of editing a post after it's been published came up. John seems to think that if you correct the information within the post, that it is ok not to let anyone know with the exception of telling the commenter who notified him of the error that it had been fixed. If one were to do their research, he believes that the reader would see the note in the comment and notice that at one time, the post had contained misinformation.