So you are talking about bugs that don't get caught in development? That happens in Rust as well. Borrow checker does not catch every bug or error. A random module you are using could throw a panic and you would not know with Rust (or any language for that matter), until your users trigger those bugs.

It sure does happen. So should we simply give up? Or should we aspire to have tools to reduce those bugs?

Knowing what kind of errors can occur is one of those tools.