The reason lies largely in the question itself: speed and accuracy are critical in the news business. Unfortunately, they are often in conflict with one another, and accuracy is sometimes sacrificed in the name of being first.
With web-based and broadcast reporting, journalists and editors sometimes make the call to publish or broadcast what they know as soon as possible and, if necessary, correct the record later. It’s not a good practice, but it does garner views and clicks, which earn money for the outlet. It is, after all, called the “news business” for a reason. Another reason, however, is that we have created a monster with 24-hour news, which puts enormous pressure on those who are tasked with reporting on crisis situations in real time.
In a case like the Boston Marathon bombing in 2013, there was a lot of pressure to make sense of the chaos and panic that spread throughout Boston that day. As we saw in class, CNN’s John King resorted to reporting piecemeal information as it came in, and as those reports were refuted, he had to report that too. It was an embarrassing display of journalism functioning less as an authenticator and sensemaker, and more as a real-time reflection of the pandemonium of that day. Although Jon Stewart’s mockery of King was funny, we should remember that live broadcast journalists must answer to different demands than their counterparts in print newsrooms. Imagine being on the air nonstop, trying to fill time, in the midst of so many unknowns.
Meanwhile, print outlets like the New York Times have the luxury of time, allowing them to verify information before they run a story. That said, some print outlets follow far less rigorous standards of verification. the New York Post, for instance, jumped on the bandwagon that began with rumors posted on Reddit and put two innocent teenagers on its cover the day of the bombing.
So, it comes down to two main factors: 1) the medium of the outlet (print, web, television, etc.) and 2) the journalistic integrity of that outlet. In a perfect world, 24-hour news would adhere to the same standards as print outlets like the New York Times, but unfortunately mistakes are sometimes made as reporters scramble to fill air time. As for papers like the New York Post, sensationalism, sadly, sells. But that’s also why the New York Post, among other outlets inclined to publish unverified and speculative reports as fact, is not taken nearly as seriously as the New York Times.