The best definition possible – and frankly, I think that will more often be a definition arrived at by adults than one arrived at by children. I agree there is a problem when a child feels they’ve been unfairly treated – whether the child is correct or not – and that’s a problem you need to resolve as best you can. But sometimes there isn’t a perfect solution and all you can do is the best you can.
We live in the real world. Perfection isn’t possible. But a solution that assumes that you can’t even come close is never going to be as good as a solution that is based on getting as close to perfection as you can manage.