Go ahead and ridicule CNN and Fox News Channel for fumbling the Supreme Court ruling (pdf) in the Affordable Care Act case today by reporting that the law had been struck down. If news organizations are going to crow about their breaking news scoops – Bloomberg News is bragging that it beat Reuters to the court’s decision by 12 seconds – they must submit to vigorous fanny-whackings whenever they perpetrate “Dewey Defeats Truman”-style mistakes. Tweets from the Huffington Post’s politics section, Time, and NPR got it wrong, too.

At least CNN and Fox only got it wrong one way. The Chicago Sun-Times erred at least four ways, posting to one Web page last night its preliminary coverage and headlines – ”Supreme Court strikes down health care law,” “Supreme Court waters down health care law,” and “Supreme Court upholds health care law,” and “Supreme Court XXXX Obama health law.” To be fair to the Sun-Times, every news organization pre-bakes as much coverage as it can when covering court decisions, elections, conventions and other scheduled news events. They write obituaries of the famous and old before they die. Pre-baking isn’t restricted to journalists. Even President Barack Obama stockpiled multiple speeches to cover three possible outcomes, he’s just lucky that he didn’t give the wrong one.

I suppose you could toss out my preconception theory and blame the errors on the continual acceleration of the news and the increasing pressure to get it first. But then you’d have to explain why Bloomberg News, Reuters, the Associated Press, and Dow Jones got it right inside the same instant news cycle.

Still, all journalism is vulnerable to error, so I forgive CNN and Fox for their breaking news transgressions. When the fog of breaking news descends, journalists often go blind or see stuff that isn’t there, a point I previously made after rewinding and reviewing the breaking coverage of the Mumbai massacre and the killing of Osama bin Laden. The early news accounts of those events disagreed violently with one another, in part, because of the chaos and the limited access to the scene. But it was also inherently flawed by preconceptions that journalists bring to every story. Reporters carry wads of pre-baked story dough to almost every breaking news story, whether it be a terrorist attack on a city or the scheduled release of a Supreme Court decision.

Obviously journalists must tote some preconceptions if only because blank slates make awful reporters. The problem comes when reporters become trapped by their preconceptions. Today, every news organization in the land knew that the Supreme Court’s decision was not limited to the simple binary of upheld or ruled unconstitutional, as the itchy fingers at the Chicago Sun-Times proved with their blunder. I’m sure that the reporters at CNN and Fox knew that, too. Perhaps they were overinvested in preconceptions about the outcome and jumped on the first confirmation they saw. That miscue was as understandable as it was avoidable, as my Reuters colleague Erin Geiger Smith tweeted shortly after the CNN and Fox screwup: “Was easy to get this wrong if you weren’t careful. Opinion headnote gives the commerce clause note first, tax on next page.”