OK he went too far, but no one was physically assaulted or killed. I've seen witnesses treat their own that way. I experienced that same behaviour at the hands of so called brothers and sisters when I was younger so I refuse to sympathise with them nowadays.
Granted, that guy is obviously an asshole and appears to be unlikeable in general. BUT some witnesses deserve that and more. I wouldn't condone picking on an elderly couple personally, but a lot of "brothers and sisters" I knew who all thought they were so big and bad and act like their shit don't stink, THEY deserve that kind of treatment and more. When you go about harassing people from door to door you expose yourself to that kind of treatment.