My handgun is a poor example.
First, it doesn't have a safety. However, the small arms I have used don't have electrical safeties with the capacity for a short circuit. I don't think the comparison or analogy will work.
And to tell the truth, I don't know what I'm talking about. I know nothing about the safeguards or triggering mechanisms on nukes. It just SEEMS to me possible that a pretty good design could be prone to compromise by a short circuit as the result of a mechanical catastrophe