As a blogger when I get something wrong, I update the post or notate what I was wrong about in the comments depending on the impact of what I was wrong about has on the story. Unfortunately our media isn't like that, when it comes to something that ends up on print or on video, they will do retractions or corrections but I've noticed a disturbing trend where newspapers, especially our local Blade, will report something incorrectly online and rather than point out a correction? Just make the part of the article that was wrong "disappear".
Yesterday this happened when they incorrectly reported a man had been shot and killed, rather than admit an error, they changed the headline and made no mention of the incorrect reporting. Some of our local television media has done the same thing when it comes to items being reported incorrectly, they just make the stories go "poof" with no acknowledgment that there was an error.
Which can create interesting scenarios on the internet when a blog writes about the incorrect information or someone comments citing the incorrect information and then others argue with them about it not being stated that way. How many people routinely screen shot media reports knowing that a story could be later changed?
I personally think it's not that hard to admit when information was incorrect or a story was updated later to include information that it did not previously contain...That to me would demonstrate wanting to earn the trust of the readers and would demonstrate credibility....