This is just unacceptable, much as we are all part of the air gun community, it's difficult to accept this kind of behaviour when it's clearly causing offence and distress to people, let along being totally illegal. Perhaps drop a not through his door explaining you were a bit upset at the time, but putting this into your own words in a friendly but factual manner? It's not good and neds to be addressed, you don't want anyone thinking it's you now do you