In this April 27, 2014 file photo, former Alaska Gov. Sarah Palin speaks during a campaign rally in West Des Moines, Iowa.  (AP Photo/Charlie Neibergall, File)

In February 2012, NBC News mangled its reporting on George Zimmerman’s killing of Trayvon Martin. In editing a police call made by Zimmerman on the night of his encounter with Martin, it portrayed Zimmerman as an out-and-out racist. By leaving out where a police dispatcher asked Zimmerman about the race of the person he was pursuing, NBC News made it seem as if Zimmerman had volunteered that information.

After much public pressure and an internal investigation, NBC News said the following, in part: “We will be taking the necessary steps to prevent this from happening in the future and apologize to our viewers.”

Those words went out to scores of media outlets, where they were processed and analyzed and criticized. They did not, however, get distributed on the same medium that broadcast the original, prejudicial reporting — on NBC News itself, that is. In an interview with the New York Times’s David Carr, then-president of NBC News Steve Capus admitted that failing to do an on-air version of the apology was a misstep.

“A network’s primary contract is with the viewers who tune in to its shows every day, one that is more important than any obligation it feels to journalistic pundits or Beltway politicos,” wrote Carr of the mess.

That’s a sentiment that CNN should heed at this time. Earlier this week, morning anchor Carol Costello exhibited brazen insensitivity to the ordeal experience by Bristol Palin and her family members in a recent brawl that has attracted a great deal of media attention. In introducing an audio clip of Bristol Palin describing the beatings she sustained, Costello said, “This is quite possibly the best minute and a half of audio we’ve ever come across. Well, come across in a long time anyway.” Just before rolling the audio clip, she advised viewers to “Sit back and enjoy.”

Costello apologized quickly and in airtight fashion: “Over the past few days I have been roundly criticized for joking about a brawl involving the Palin family. In retrospect, I deserve such criticism and would like to apologize.” That statement was sent to Politico, but not said on-air.

The Erik Wemple Blog catches Costello’s CNN show daily — and thinks sky-highly of her anchoring work — but didn’t catch any moment of regret mirroring what she told Politico. A CNN spokeswoman confirms no such event has taken place. It must. CNN surely has more regard for its audience than to pass along such an important message through a bunch of media blogs.