All of which seems vaguely familiar. Unless I'm mistaken, newspapers have had this sort of difficulty in the past. Some even run a regular column of corrections. When it was brought to the attention of Wikipedia they did the same and then added the controversy to Mr. Seigenthaler's bio.
The reason that the story has received the furrowed brow treatment is twofold. First, any story that involves members of the club get the sort of loving care that you would give your own family. They're interested in what others in the business are up to and by golly you must be too. Some members have made the mistake of forgetting their password. Judith Miller, Bob Woodward, Bob Novak and anyone at Fox News failed to recognize journalistic standards--never acknowledge contrary views. But most are dues paying members and march in lockstep.
The second reason has to do with the siege mentality brought about by rapidly evolving methods of delivering news. Traditional news outlets are losing their source of money--ink on paper--and haven't been able to replace it with internet delivery. Newsroom layoffs are now routine. Into this arrives an interesting rival, a source that carries with it some of the same flaws that print journalists have had to contend with. Rather than acknowledge the similarity, they attack as if their life depended upon it. Witness weakness.