Regardless of the details, that things escalated to the extent they did can almost entirely be attributed to it being nobody's job to resolve this earlier. Engineers get paid for shipping code. Executives ensure that the company is moving in the right direction, and often the concerns of one engineer are rounding error. People need to be able to say: "If things happen, I will go to this person, whose long-term success at this company is entirely determined by the success of this particular half-dozen of us."