I personally would still go after the kids parents. Of course, most everybody is glad the kid didn't hurt himself. That's besides the point. Even if he had, it wouldn't be your fault. The kids parents should pay up for sure. Because of the way the daycare is set-up (somebody's home), no doubt their insurance would have to step-up too as this kid was in their care at the time of the "accident."
What would you do if your kid dumped somebody's bike?
