Vice President Joe Biden may yet launch a presidential campaign. But so far, he hasn’t.

For about three minutes on Monday night, however, The Post was saying he had. This was a mistake, of course. What appeared so briefly on was merely the draft by veteran congressional reporter Paul Kane of an anticipatory story — just a news outlet doing its job of preparing for a distinct possibility, if you believe all the pundits out there.

Post Managing Editor Emilio Garcia-Ruiz tells the Erik Wemple Blog that a couple of staffers had opened Kane’s file and were “in a hurry to append a video” to it. In the process, they “accidentally published it.” The mistake occurred via button confusion. “They were supposed to press one button; they pressed a different button,” says Garcia-Ruiz. A quick uh-oh ensued. “They realized their mistake immediately and it was removed from the Web within three minutes,” says Garcia-Ruiz.

Three minutes is an entire, leisurely Sunday afternoon for the screen-grabbing, text-capturing Internet; the disappeared story appears here.

Other news outlets know enough not to mock, given the universality of accidental publication. It happens every so often, commonly with obituaries of aging famous people — artifacts that sit around unpublished for years. In any case, few publications are able to boast that they’ve never had to pull down an unintentionally published news piece or tweet or Facebook post. Disclosure: The Erik Wemple Blog once prematurely published a piece on the spat between MSNBC’s Rachel Maddow and PolitiFact. The piece was only slightly more incomprehensible than a “finished” post in this space.

“We have made absolutely zero mistakes,” jokes Meredith Artley, CNN Digital’s editor in chief. “When this happens to a competitor . . . there is only empathy and commiseration . . . zero Schadenfreude, zero amount of mean-girl glee. Everybody understands how easy this is.” CNN each day posts hundreds upon hundreds of items — articles, video, photos, the works. The CNN content management system (CMS), says Artley, is equipped with “flags and tags” to guard against accidental publication. When a staffer hits publish in the CNN system, for example, they find a pop-up dialogue box asking what platform will be hosting the piece of content — a step that protects against accidental publication. There’s a separate dialogue box that surfaces for stories that are originally tagged “held for release.” Here’s a screengrab of the CNN CMS in full “HFR” action:

And here’s the routine “publish” dialogue box:

In situations where the story is “super confidential,” says Artley, staffers will work on the piece outside of the CMS, reducing to nil the chance of accidental publication on CNN platforms.

About a year ago, the New York Times prematurely published a TK-heavy story on a Senate vote regarding the Keystone XL pipeline. Asked about the episode, New York Times associate managing editor for standards Philip Corbett responds via e-mail, “Well, mistakes happen, here and everywhere, so I have nothing but sympathy when this happens to someone else.”

There are two different buttons in the New York Times publishing system that need to be clicked to “ready” before it premieres on, adds Corbett. To add a greater dash of precaution, those buttons are “typically clicked by two different people — most often a web producer and a copy or slot editor.” Solid! But not foolproof, notes Corbett. “[E]rrors are more likely on breaking news when everyone is working fast and trying to have things ready to publish at a moment’s notice,” he says.

When mistakes do occur, publications have to consider whether the screwup was an extreme outlier or whether it merits upending workflows to prevent a recurrence. “This particular circumstance has never happened before, but we will look into making whatever changes we need to make to make sure it never happens again,” says Garcia-Ruiz of The Post’s recent experience.

And don’t get the idea that this phenomenon started in the 1990s. “I’ve been around long enough to know that we’ve published dummy type or wrong versions of stories in the good old print paper, too,” writes Corbett. “And then you can’t fix and repost it!”