Plenty of blame to go around.
I would also add that the owner having his dog sit on a seat while people are standing is rude.
That totally dismisses that the owner ultimately could not control is dog.
A dog is going to run into people, some going about their business and others jerks. If you have a vicious breed, there is no excuse, no blame to go around. It is the owner and the dog only. The condition in public is known.