If you full-board your horse, do you expect the barn staff to install manners in him or her, or do you believe it is your responsibility to make sure your horse respects his or her handler on the ground?
Similarly, if you work at a barn with full-boarded horses whose owners may not be around much, how would you handle a very VERY rude horse? Would you take extra time to work with the horse, or just deal with its nonsense every day? Would you contact the owner and ask them to do something about it?
I'm talking about blatantly rude, disrespectful, and potentially dangerous behaviours. Spooking into the handler, disregarding the handler's personal bubble completely, refusing to move forward, pushing the handler around with the shoulder, yanking the handler around, etc.
(we got a new boarder. the horse is quite rude. I'm not impressed.)