That was a very interesting video but I think you misrepresent it slightly. Its clear the Estonian E-voting system was designed very very well in comparison to the ridiculously bad Diabold machines of yesteryear. The problem was that the current state-of-the-art hasn't advanced enough to make major fraud at least as hard as the paper ballot. And that means that e-voting makes it plausible for state actors to dictate election results, which in a democracy is a very bad thing. In other words, there was no way Estonia could make it perfect and anything less than perfect is broken.

The important point for me was that getting e-voting right is so incredibly important to a democracy that it should be treated as a national security issue. The Estonian E-voting system was clearly treated as a government IT project as procedures like "don't plug in a personal USB stick into the master counting server" are violated if its more convenient than replacing the broken DVD drive. Worse, politics gets mixed in which means that security concerns are dismissed with complacent and technically questionable statements like "nice people who care about computer hygiene have no viruses".