I'm going to propose the opposite: no one should be held accountable for an AI agent that acts maliciously by accident.
I think someone could argue (and many do) that inserting a piece of computer software (AI) in the middle lowers the level of intent and thus the level of responsibility, but having a particular type of software in the middle absolve one of responsibility seems unworkable and poor public policy.
Sadly, software "engineers" are not held accountable for their profession like everybody else with a real engineer title. And AI companies are all building Ford Pintos as fast as they can, and competing with each other about who's product makes the biggest explosion.