Ok they turn off the guardrails on a system in testing. The model escapes and causes 10 trillion in damage. What does liability even mean in that case? You have an autonomous system that's escaped your control and is wrecking havoc. And while you can throw people in jail it doesnt do a damned thing about solving the situation.
Your question is a little like asking why we arrest arsonists when there are fires to put out. The law does not need to choose.