I don't think that was a scammer, just a new player that really wanted a pirate hat.
When you play this game, you must realize that you'll run into players that are just starting and will try to trade a bunch of new player items (NPC pins and cheap stuff from Small World Imports) for your extremely rare item. This is absolutely normal as they are new to the game and have no idea what is rarer than what.
I think you were totally unjust in what you did. I am especially discouraged that you reported this person, leading me to believe that you must have an age limit of when you are allowed to report other players.
The Report function is to help make the game safer for new players, not try to get them banned.
This is not something that you just do willy nilly. You must discern when the right time is to report someone.
People get banned from VMK for the silliest reasons, and you, my friend, are part of the problem.