This is a really good observation, and wow I'd never remarked on the hard hats but now I picture it, it's absurd!
I was taught that perfect people won't , foe example, slip and fall from a roof. But of course that's only considering human error....There are many factors that can go into an accident as you say. What about chemical reactions? Will god change physics itself so rust isn't a thing? Metallurgy?!! I know it's answering a question with a question, but it's by way of agreeing with the absurdity of the paradise proposition!