My thoughts go out to the injured window cleaner and his family, I just hope he was insured.
I was speaking to one of my customers yesterday, its the first time that I have seen her ( only been cleaning her windows for the last 2 years) anyway before I started cleaning her windows, she had a window cleaner who used ladders who tried to sue her because he fell off his ladder and broke his back.
He fell while trying to clean a window above a sloping roof, his insurance would not pay out so he tried to sue her instead, her insurance refused to pay because he should not have been using ladders to clean this window which was above a sloping roof, he instead should have used an alternative method accordingly to them.
So for all those window cleaners who are paying for insurance, I would check whether they will pay out if you did have an accident, and for those who think they can hold the customer responsable, then you will need at least a written order that you are to use ladders.