WASHINGTON – A former top intelligence official who signed on to a letter attacking The Post’s bombshell 2020 reporting on Hunter Biden’s laptop as Russian disinformation has now admitted he knew a “significant portion” of the recovered files “had to be real” – but doesn’t regret dismissing the exposé. ... The Oct. 19 letter — whose signatories included former Defense Secretary Leon Panetta, former Director of National intelligence James Clapper, and former CIA Director John Brennan — went out of its way to cast doubt on the legitimacy of The Post’s scoop, devoting five paragraphs to explaining “factors that make...