I hope your dads ok,it really isn,t a good idea for your dads blood to boil like that at his age but what else can you do in that situation.
He deservs a medal having to go through that,i hope this doesen,t have a to big of an affect on him phisicly and mentaly but for him to try and see the good and strong points and feel duly proud of himself,which he more than should do standing up to those evil b*****ds.All the best