I'm not Mark Knopfler's lawyer or something, but I believe all this stories about Mark being rude are hugely, deeply exaggerated.
You can check out this cool video of Penn Jillette from Penn & Teller, where he discuss how being famous and rude can collide:
(contains bad words, you've been warned)
So, maybe the dentist was really bad and deserved a bag of coins, maybe Manu Katché deserved talking to him in third person or something. Maybe sausages really was "the final straw" of crew's mistakes, we can't know either. We will never know, especially when everybody tend to surprise you with Mark being rude.
As for Mark's brother, I was in exact situation like him — I stopped talking with my brother for like 10 years, or he stopped it, I really don't know to this point. Then, after all these years, all of the sudden we started to talk again, but it was like "Hi, how are you doing?" since then.
What I like to say, is that this tells you nothing about human qualities of both of us. It's just between us, and to others we're just "normal".