> Every design failure starts with an engineer hand-waving how something bad won't/can't happen. Yes, but the converse is not true: when one <hand-waves how so

> Every design failure starts with an engineer hand-waving how something bad won't/can't happen. Yes, but the converse is not true: when one <hand-waves how something bad won't/can't happen>, it does not necessarily mean that <there will be a design failure>. You are trying to say that act A causes consequence B because many instances of B correlate with A. That is not sound.