Faced with reporters calling him on his dishonesty in his latest campaign commercial, McCain doubles down and stonewalls. See Kos, Who's Lying? John McCain or Andrea Mitchell?.
In my opinion this is a very serious error: the political press will stick to its 'objective' he said/she said approach no matter how ridiculous the issue except for facts they personally witness. You can bamboozle the press with fake numbers if you can find one economist to vouch for them. You can say your goal is a balanced budget and world peace while you propose huge deficits and wars (worked for Bush!). But you can't tell the press not to trust their lying eyes.
I'm surprised that McCain has learned to take the press so much for granted that he thinks they will sit still even for this. I think it may reach up to bite him — at least until he makes nice again.
Its not an error for the same reason Novak running over that pedestrian and driving away was not his fault.
I think that the truth here is that McCain is not lying, he genuinely cannot remember what he said only days before. That sort of thing happens to people when they get to their mid-70s. McCain seems to be losing his marbles somewhat earlier than most. Some people are sharp as a pin at 90, others like Terry Pratchett have Altzheimers at 60.
Of course that does not give the press a pass for covering up McCain’s inability to meet the demands of the campaign trail, let alone the considerably more severe challenge of being President.