It actually should depend on whether the White House gave the reporter any information that led to his story or if he just made it up.
The White House wouldn’t have released information about the surprise trip for security reasons. So if asked, how would they have responded?
I’m guessing the reporter was assigned the story, couldn’t get anyone to talk and so made up the story. And if so, he should be fired. But if he had a valid source, then firing seems a bit harsh.
Making an honest mistake under these conditions would be understandable.
The real problem was the venom and snark of the article. She was writing for a diminishing core of readers who just lap up "news" sources like Newsweek.
It wasn't a mistake like, "The President plans a quiet holiday at home." That could have been covered by a correction that said, "Obviously, we didn't know the details of the President's trip." And it would have been no big deal.
Instead, it was a typical Orange Man Bad story. She and Newsweek looked like complete hacks, and no amount of corrections could have fixed it.
A whole lot of people are tired of this kind of garbage.
No matter what when it came out that he was with the troops, the golfing part of the story was false and should have been corrected. But it was left in the Headline as well as most of the body. Visiting the troops was “and more”. And only mentioned at the bottom of the article. It was clearly misleading in a very obvious way.