Due to my experience with full hookups, I'm finding it hard to believe there was any smell. How many people can honestly say that they can smell bad odors when dumping at a full hookup site? I never have.
If the connection was that close to the OP's patio, then his problem most likely has to do with the act of dumping water and the smell part was added in to infuriate others, who in typical RV.net fashion, snarled and bared teeth.
And again - if the guy was that close, a simple conversation/question would have solved the problem instantly. I'm giving the guy the benefit of the doubt - maybe you should as well.
If that makes me not worthy of camping next to you, then feel free to get resolution from ranting about me on an internet forum.