I thought the explanation was not that Diebold stole the election so much as that the computers massively counted the vote wrong, as computers are often prone to do. And that the discrepencies found should be regarded as sufficient evidence to audit the vote, not only in this vote but in all future votes where similar discrepencies are found. Except of course that Diebold machines can't be audited. Which is exactly why these sorts of machines shouldn't ever be used again. Rather than installed everywhere.
I personally find the argument that Cleland was gypped by the machines pretty convincing. I don't see any need for a conspiracy theory to go along with it.
Michael