Happens quite often and sharing knowledge with a person like that is usually wasted time in vain.

The solution: Shoot high score. Last time someone confronted me I shot high score on the trap line and put the gun on the rack and walked away.

A little while later a few shooters not involved who overheard the commotion go by the rack to look over a 122 year old Parker with Damascus barrels. They come find me and we talk guns and we have an open and positive discussion about Parkers, other vintage SxS, and barrels.