I was just told about an incident, where a tiny female jujutsuka was attack by a huge strong man. She was sued and fined for violently injuring him.
Unfortunately as silly as this is, thats the society we live in now.
If someone tries to rob (and possibly kill) you and you defending yourself end up really hurting him, well guess what.... you're going to have to pay for his injuries. Thats probably subject to argument but I think there are ample cases where injured criminals while breaking the law get hurt and turn around and sue someone.
Right out to lunch.