As for crediting the news organization which broke some piece of news, that’s more of a journalistic convention than a necessary service to readers. It’s important enough within the journalism world, at least in the US, that it’s probably a good idea to do it when you can. But most of the time it’s pretty inside-baseball stuff. And in the pantheon of journalistic sins, failing to do it is not a particularly big deal. What’s much more important is that your reader get as much information as possible, as efficiently as possible. Which means that if you’re writing about a document or report, you link to that document or report. Failure to do that is a much greater sin than failure to link to some other journalist.
So while sometimes the failure to link is unavoidable, I look forward to a time when journalists face much more criticism for not linking to primary documents than they do for not linking to some other news organization which got the news first.