CNN got the call wrong on the Supreme Court and the individual mandate. They then tweeted it, put it up on their website, put in as a banner onscreen etc etc. Then news began filtering in that the mandate had been upheld as a tax. What should they do now? There is an interesting blow by blow account of what happened by Tom Goldstein on SCOTUSblog. He adds:

Ironically, CNN reacted too slowly in part to avoid a second error.  The network did not want to be in the position of reporting that the mandate had been struck down, then reporting that it was upheld, then reverting to its initial report.  (That had happened to the media in the 2000 presidential election, and it had been a debacle.)  CNN gravitated to an intermediate position of uncertainty on the air, which of course was not decisive enough to correct viewers’ initial impressions.

CNN had also converted itself into an integrated circuit in which its electronic media teams were tied directly into the broadcast operation.  But not anticipating the possibility of an error or confusion, its first web, electronic, and Twitter reports did not hedge.  And the network did not have a clear plan to reverse the circuit on the electronic-media side and tell readers that its initial reports may have been wrong.

Once CNN made one mistake, it was hard to admit it because they were operating in an open environment with other players judging their actions. If CNN were operating in isolation – like an individual deciding whether to invest in a healthcare company – they would have reacted rapidly to correct their action given their latest information. But in an environment where others are watching them, they have to make future decisions which are consistent with their earlier error.