They are a serious journalism organisation so you can assume that they did have multiple sources (which they stated they did). And yes unnamed sources are corroboration just as they have been during every major news story that has ever broken.
And pretty sure journalism started to become a tribal force about 20 years ago when Fox News launched. It is the same approach Murdoch took with papers in the UK and here in Australia.
And pretty sure journalism started to become a tribal force about 20 years ago when Fox News launched. It is the same approach Murdoch took with papers in the UK and here in Australia.