I am so sorry for that experience!! I house/pet sit for friends and neighbors, and I make a REAL point of treating their animals as if they were my own. Chickens included. I follow any instructions listed, carefully, and don't understand some people's work etiquitte is lacking. I am sorry about that
I have learned to be very picky for my pet sitters, and that even EXCLUDES some of my housemates/family members. If I am not home to care for my chickens and nobody else has the knowlage/willingness to do it, I find somebody who will, or don't go. <--none of which is directed at you lol!! I am venting frustation at your sitter as well
sorry again