The misstatements are perfect precisely because they can be chalked up as mistakes. This gives McCain the ability to claim that he didn't mean what he said when fact checkers call him on it, but when not confronted with reality, he can get his message across to those who don't follow the details.
The whole thing is a revival of the Bush Administration's tactics to get us into war with Iraq...to say things to suggest more than even their flimsy evidence would support. But the literal meaning of the statements allowed them to wriggle out of what they had hinted at. [Like the famous 16 words, "The British Government has learned that Saddam Hussein recently sought significant quantities of uranium from Africa."]