In this case I would replace "stupidity" with "assumption". It was code-reviewed so that level assumed correctness. It's in OpenSSL, which is written by experts, so the millions of us that use it every day assumed correctness. Our customers know little about the workings of the internet, so they assume correctness.

This, incidentally, is the same sort of thinking that sometimes kills experts in dangerous situations: the assumption that someone smarter than us must by definition know more than us, so we can be lackadaisical. Witness Snow Fall (http://www.nytimes.com/projects/2012/snow-fall/?forceredirec...)

The rest of the quote is "...but don't rule out malice."