I would not say that it a sign of things to come but certain segments of society like to push people around.
As to what to do, I'd definitely have contacted the police. What if it had been someone less capable of defending themselves? A young woman as an example?
I ride where I ride when I want to ride and I am very considerate of others that I meet out on the road.
That said, I don't abide by thugs, rednecks or dogs that give me grief.