Perhaps it was unclear in my first post -
The neighbor (let's call him neighbor 1) that implied that he had heard about our conversation was not a party to the conversation. The neighbor (neighbor 2) that I had a conversation with, is in a dispute with the neighbor (neighbor 1) that implied that he heard the contents of our conversation. Neighbor 2 did not report the conversation to neighbor 1 because they are in a legal action with one another. The only possibilities are that neighbor 1 received the contents of my conversation with neighbor 2 through the use of an electronic survelliance tool or somebody in the neighborhood was eavesdropping on my conversation with neighbor 2.
Does that change the answer?

