Erm. I’d definitely consult with a lawyer.
Gross negligence is a legal standard. A lawyer who brings up “gross negligence” is inviting us to consider not what is right or what is just, but what meets the technical standards of the law. And since I haven’t gone to law school, I can’t rightly comment.
I’m not sure the gurads owe a duty to the victims. I would hope, that in general, that prison guards do not owe such duties to crime victims. They may owe some duty of care to prisoners, and staff who may be injured as result of negligence, but inviting them to assume a level of duty to crime victims invites things like torture.
