I was going to say something similar. In the Therac case, at least part of the fault fell with the operators who should have known what to look for (if things had been well documented and they'd been trained). But this is a rare event, every year (at most) or every 2 or 4 years, for most voters. You expect computers to work these days and to be responsive so the idea that users are at fault for crappy UI/UX is absurd. If something seems to be working then the user in this case has no reason to doubt it because they haven't used these systems with sufficient frequency to be aware of its poor quality and how to respond to it.