Sounds like people are mistreating Rex and you, Rex is soooo handsome!
I would think people would not want to rough around or be confrontational around a strangers German Sheperd, i know a few who are VERY protective like the Rott, i dont think you should have had to pay, those kids provoked Rex and then said nasty things to the two of you, i would have told how the kids kicked it to my Dog and been very angry. Sorry you had to pay