Holy crap dude, I already told you I don't know what methods they used. An election fraud task force spent two years examining the voting records of twelve counties in the hope of discovering fraud. Different types of fraud were discovered to have been committed among twenty people. Unless you know the task force excluded this type of fraud in their investigation I don't know why you're assuming they did.

So, third time's the charm I hope: You said "they didn't verify that every confirmed voter voted." When something like this is written as a declarative statement, it means that you are putting this forth as a fact. To be more specific, you are saying that they really did not do this. For the last time, how do you know this to be the case? (And no, the fact that they did not call everyone who was said to have voted and asked "are you X? Did you vote in the 2008 election?" is not evidence that they didn't look into it, possibly for no other reason than that it would be the single dumbest way to investigate such a thing.)