His conclusion? The process is actually pretty good, but part of that is a factor of the size.
What are the lessons here? First, open systems conducted within a known group make voting fraud much harder. Every step of the election process is observed by everyone, and everyone knows everyone, which makes it harder for someone to get away with anything. Second, small and simple elections are easier to secure. This kind of process works to elect a Pope or a club president, but quickly becomes unwieldy for a large-scale election. The only way manual systems work is through a pyramid-like scheme, with small groups reporting their manually obtained results up the chain to more central tabulating authorities.
And a third and final lesson: when an election process is left to develop over the course of a couple thousand years, you end up with something surprisingly good.