And proper response is to yell back "You almost had the dog on the leash there for a moment! Almost!"

That would probably bring the message across if they are able to comprehend. But hey, I came to expect such things when riding, so always have brakes ready and expect the most innapropriate action from everything in your way - if there is a pedestrian looking right toward you and plainly being abe to see you coming, you can be sure he will step right in front of you just as you're about to pass him