Melodramatic mea culpas can attract traffic too. Getting a story wrong can thus provide a two-fer: one batch of attention for the sloppy, inflammatory first piece, then another for the contrite (or alternatively, defiantly unapologetic) correction.
Ever see the movie 'The Corporation', which diagnosed the 'person' of a corporation as being psychopathic? Well, the DSM-IV diagnosis for an ad-supported blogging site will tend toward Histrionic Personality Disorder†. Clickonomics almost demands as much.
† http://en.wikipedia.org/wiki/Histrionic_personality_disorder
"Update: Regarding Evan Williams’ statement here [link to http://twitter.com/ev/statuses/801530348], all I can say is that multiple sources claim that Twitter is telling people they are planning on moving away from Ruby on Rails. This is not the first time a company has denied something that has turned out to be 100% true."
"Lots of our code is not in RoR, already, though"
Sounds like an ongoing process rather than a new thing
Most successful LAMP sites use software from more than one bucket. That is not news.