"But the fact that only a few reporters decided to print these rumours in their entirety PROVES [capitals = my emphasis] just the opposite: that the vast majority of American publications – even ones Mr. Trump usually dislikes! – aren’t out to get him, but that they’re simply out to tell the truth, when they can verify it."

Actually, this one incident does not PROVE anything.  It simply represents evidence on one side of the case for journalists being interested in telling the truth.  The completely illegitimate use of the word "proves", in that context, constitutes evidence on the other side of that case.