As already said it did not appear in print, and perhaps one should read the source from whence it came, The New Your Times no less, who seems to having a go at Brexit and the UK's tabloids.
https://www.nytimes.com/2017/05/02/world/europe/london-tabloids-brexit.html?smid=tw-share&_r=4
/// I had met Mr. MacKenzie a week earlier to ask about those headlines. “Your front pages were sometimes funny and sometimes outrageous,” I began, at which point he interrupted and said, “And sometimes untrue!” ///
/// Wow. ///
/// I asked what headline he would like to see in the paper were he still in charge. ///
/// “I think the fake news headline that would give this country the most joy,” he replied cheerfully, “would be ‘Jeremy Corbyn Knifed to Death by an Asylum Seeker.’ ” ///
/// Mr. Corbyn is the leader of the Labour Party. Mr. MacKenzie’s fake news headline inevitably brought to mind the murder of Jo Cox, a pro-Remain Labour lawmaker who was killed by a man with far-right leanings a week before the referendum. Her death prompted a lot of soul-searching over whether the tone of the campaign had encouraged hate crimes. ///
/// (The next morning, I got a text message from Mr. MacKenzie: “Hi Katrin, Can you change that perfect headline from ‘Jeremy Corbyn knifed to death by asylum seeker’ to ‘Jeremy Corbyn Defrauded by Asylum Seeker.’ In the light of Jo Cox murder mine is in tol poor taste.”) ///
It was all a humorousness joke between two people, all be it in bad taste.
He later thought about it and sent a text saying "change that perfect headline to Jeremy Corbyn Defrauded by Asylum Seeker." due to the Jo Cox murder.