In my country, engineers are legally responsible for their work to the point where insurance is required to do engineering. And yes, engineers that are negligent are held responsible. Just because you're ignorant doesn't mean it doesn't happen.

Certainly liability insurance exists.

Let me know if find answers to my questions.

You know any software engineers with liability insurance? Also, you would have learned of many examples had you gone to engineering school, we have whole courses dedicated to laws and ethics.

Yes many software engineering firms hold liability insurance.

And many software engineering contracts contain liability clauses.