"Mens rea" just means you have the mental state required for the crime. Negligence or recklessness are mental states, so they can satisfy the mens rea requirement if the crime is defined that way. For example, recklessness or gross negligence can satisfy the mens rea requirement for vehicular manslaughter.

But negligence is evaluated from the point of view of a reasonable person. Would a reasonable person foresee that telling an AI to do that could cause it to do illegal things? We'll likely have to develop that through case law as the facts develop.