> Another variation on the problem is the over-allocation of resources to preventing problems which actually happened once, versus those that are more severe but haven't happened yet.

I've heard this called "institutional scarring" in a blog post somewhere. The idea is a small wound can be replaced with tough inflexible tissue. The jist of the blog post was that just because something happened, doesn't mean you have to change things to ensure it never happens again because that can be an over-reaction that really burdens your future. Accept that loss and that it just might happen again, but that may be better than onerously preventing it with certainty.