The first "no" never sets a clear boundary in a conversation or negotiation. Any salesperson who accepts the first no, wont be making sales. When dating, accepting the first no means you probably wont get laid much.. Think about this, if you saying no set a clear boundary, why did you continue to talk and engage with this person? If the boundary is not clear to you, how could it be to another person ? Your basic premise is you don't talk to aggressives, yet in both your examples, you do just that. Obviously, how you deal with Max and his wife Zelda from the great state of Kansas will probably be different than how you deal with a crackhead on the street.
PS. I actually met Max and his wife in downtown Montreal when they were attending a Shriners convention. And yes, that is how he introduced himself to me on the street as he approached me.