Far more accidents have almost happened than is publicly known, but then smarter men—on both sides—have always prevailed. this is because it is real life, not a spy or war movie or novel.
Those men remain in the background and don’t make stupid political threats or post what ifs.
Thank God smarter men than selected leaders.
But anything can happen, as you say. If it does, life will be very hard for the survivors. There will be no winners.
Unfortunately, I've also noticed over the years that the vast majority of people think they know more than they really do - which is a potentially fatal tendency, if the structural engineer was correct (and FWIW, I believe he was).
As you say, thank God there are smart men on both sides, but anything can happen...
I never see anyone describing how a small nuclear exchange wipes out the nations involved for generations, not in body counts but in economic and social systems.
Wouldn’t the countries involved in a limited exchange hitting a few of their economic and population centers be somewhat removed from the world stage for a few decades while their economies and economic structure recovered and those economic hubs and the people and data making them up were replaced?