[Noney]

Your neighbor is simply voicing to you (in what sounds like a not-so-neighborly way) what several of us are saying, and that is that free-roaming cats are causing him some personal issues. It is not up to you to decide how trivial or not those issues may be. He came to you because he has seen your cat on his property and is trying to tell you that he is about to do something about the situation (kidnapping) and is warning you in advance. At this point, it doesn't really matter to this guy if it was in fact your cat that committed the actual offense. It sounds like he has finally had enough of the cats and is going to act.

My guess is that you are about to see a lot fewer stray cats in the neighborhood.