As someone with a poor sense of balance, I consider it my own fault when I fall. It is my responsibility, as an adult human being, to be responsible for my own actions, and to be careful. If I am not careful, and I fall, it is my own fault. I can SEE if the sidewalk is uneven if I bother to look.

Does the "faller" not have health insurance? A lawsuit's gonna cost a whole lot more time and money than a doctor bill for a small fall ...