Also, it takes an extremely precise sequence of events to cause a nuclear detonation. A nearby explosion is not enough to do it, as you can obviously see here.
tldr; The socket didn't properly fit the wrench and they had to manually hold the socket on the end of the wrench. One man dropped the socket, which fell through a small gap between the walkway and missile. The torque wrench was large enough that it would not have slipped through this gap if/when dropped.
If you're dealing with technology so complicated that one person cannot simultaneously design and repair / maintain it, then whoever performs the latter doesn't possess all the knowledge of the former.
Maybe they used an flammable alloy under certain conditions for engineering reasons.
Most metal doesn't burn. But do you want repair / maintenance techs making that assumption?
Multiple by 100,000 parts.
PS: A more realistic example was one of the Skunk Works projects. I forget the details, but either tools of special metallic composition or wooden tools had to be used to avoid damaging the flight characteristics of the aircraft.
Livingston died as a result of that explosion.
This seems tragic to me. I can't believe someone would "order" him back into the silo to turn on an exhaust fan. First, starting a fan motor inside of an explosive environment can be dangerous. Second, how could someone have such disregard for another person's life, that they send him into a room full of explosive gas?
Perhaps the stakes seemed so high, they felt the only way to stop the warhead from scattering radiation in a resulting explosion was to exhaust the silo.
Ordering people to take potentially fatal risks to avoid greater harms is not merely recurrent within the military, it's fundamental to it.
That doesn't mean that there can't be room to debate whether a particular risk ordered was warranted, but one absolutely should not be shocked that a military superior ordered a subordinate to do something that involves a potentially fatal risk.
This is the military: it’s sad but not out of scope to order someone to do something dangerous, or even likely fatal, in order to accomplish an objective. Consider “you stay here with this machine gun while the rest of us go back the way we came.”
I can't remember which fusing system was on that warhead (though the book describes it in detail) but I think it was one of the more sophisticated kinds than the simple "one point safety" fuses and that the warhead was basically never in danger of exploding.
It may seem like micromanagement, but small seemingly meaningless deviations from procedure can add up to big problems, particularly when dealing with space.