I can see why you wanted to ask that question... but I take issue when you say it was the only question you could ask...All I could ask was, "why were you so angry at that gun?"
I mean -- did it not occur to you to ask the fellow why he waited SIXTEEN YEARS to show up and see about his gun?!
As for the guy being irate...
If it was the same shop with the same ownership, I suppose I could see him with a case. Otherwise, I'd give him the (last known?) address/number of the previous gunsmith, or just his name if that's all ya had and saying, "Pal, this could be a flower shop or a Burger King you walked in to. It simply happens to be another gun shop. But it's not the business you left that ugly gun with, so enjoy your quest somewhere else."