Oh dear. After the Guardian ran a story claiming Jeremy Corbyn was unable to find a seat on a Virgin train journey, a media storm shortly ensued when the train company responded by releasing CCTV footage to the contrary.

Since then, it's been revealed that the freelancer behind the story was actually a campaigning Corbynista who wasn't even present on the train journey. So, why did the Grauniad publish the story in the first place? Happily -- if a tad too late -- hacks at the paper have been asking themselves just this of late. Following an investigation into the error, the paper has published its findings -- and they don't make for pretty reading.

In a piece on the issue, Paul Chadwick concludes that '“Traingate” seems to have developed as much from Guardian flaws as Guardian strengths'. It turns out that the story was first pitched to Buzzfeed, when the website rejected it the video was passed to the Guardian on the condition they included Charles B Anthony's article with it. Staff at the paper then failed to query any facts in the story -- as they might with another freelance offering. Instead it was 'mistakenly treated by the Guardian more as freelance journalism than what it actually was: a kind of gonzo news release by two Corbyn supporters'.

What's more, hacks at the paper were aware that Corbyn had obtained a seat on the journey. Alas they failed to include this detail in the story.

Good to see the paper are taking its 'facts are sacred' mantra so seriously.