I genuinely don't see how anyone could ever enforce a "remain in your seat until the bus has stopped" policy. I've been injured (slightly) in the past when a bus driver performed an emergency stop when I was getting up to alight: this did result in a complaint to the bus company, but it was only as part of a list of failings of that particular driver (viz. singing and swearing coming from the cab, dangerous driving round roundabouts, failure to stop upon the bell being rung, etc.) I'd certainly never have dreamed of seeking compensation from the bus company.
I always understood the "please remain seated until the bus has stopped" signs as disclaiming the bus company from any responsibility if you choose to stand while the bus is in motion, rather than a steadfastly-enforced rule.
I always understood the "please remain seated until the bus has stopped" signs as disclaiming the bus company from any responsibility if you choose to stand while the bus is in motion, rather than a steadfastly-enforced rule.