Some newspapers never admit mistakes. Some papers issue corrections. The Times-Picayune?
They admit mistakes, scrub the commentary from the print edition, erase it from the online version and delete letters responding to it all. See Kevin Allman's blog for plenty of visual evidence on how the Picayune tried to hide its offense to hizzoner.
I think it's safe to say that Nagin made the Picayune his bitch.