Paper ballots are a must, I agree, because they can be counted by hand, but they don't have to be, at least not at first. Electronic counting/scanning of paper ballots can be trusted – it's not that difficult to verify the counting for a small (known) set of test ballots and use the machine to count the rest. If there's doubt, then hand-count... but hand-counts are fallible too – mainly because the human is the weak link, of course (we make mistakes, even when we try not to) =)