Weigel said he deleted the photo after another reporter "told me I'd gotten it wrong".
'An hour later he tweeted: 'It was a bad tweet on my personal account, not a story for Washington Post. Weigel responded by tweeting out a photo of the rally that seemed to show several hundred empty seats.
However, US President Donald Trump was not satisfied with frank apologies and instant response by The Washington Post journalist and suggested firing Weigel.
Weigel responded in three minutes and apologised for his mistake.
Trump didn't hesitate to throw ABC under the bus as well for "fraudster" Brian Ross' erroneous report on former national security adviser Michael Flynn, claiming the network should've fired the now suspended reporter. At Friday's rally, Trump also criticized both ABC News and CNN, the Hill reports.
Mr Spicer said at the time the actual number who attended was unknown - before insisting nonetheless that the new President had attracted "the largest audience ever to witness an inauguration" anywhere in the world.More news: Meteor shower to fly across Norway's skies
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At Friday's rally, Trump pointed to a CNN correction and other corrections and clarifications by news organizations in the past week on stories that initially had been damaging to the president but didn't live up to the scrutiny.
In fact, the email to the younger Trump was sent a day after the documents, stolen from the Democratic National Committee, were made available to the general public.
Mr Weigel's tweeting has previously landed him in hot water with the newspaper, with bosses issuing a reminder to its reporters that their online behaviour is an extension of their professional lives after the journalist branded defeated congressional candidate Dan Bangino a "lying, pathetic loser".
He continued: "CNN'S slogan is CNN, THE MOST TRUSTED NAME IN NEWS".
Reporters asked spokeswoman Sarah Huckabee Sanders about the president's fondness for attacking some things as fake news while choosing not to attack false news reports allegedly circulated by Russian Federation during the 2016 election.
Even if the photo had been a legitimate representation of the crowd-size, directly jeering the president in this way is still outrageous behavior from anyone who describes himself as a legitimate journalist.