LOL, every media outlet that is now reporting the story as a headline is quoting the Guardian, including the Daily Mail. It is perfectly normal to report stories from trusted sources and specify the source. They will have attempted to independently verify. Do you realise how little news each newspaper would actually contain if they only reported on stories where they were the original source!? You seem to not understand journalism basics.
You're also criticising the BBC for running a headline story in the evening rather than waiting until the next morning like the rest of the media!? lol again. What sort of bizarre 'waiting your turn' journalism do you think the media companies should employ. Don't have a clue!