Sounds like you found a bug and a potential exploit. Since nothing ever really changes hands or in fact even exists, I would like to imagine that since you got the money, the buyer also got the item. You probably would have gotten an IM or even some ingame mail if they hadn't.
You might want to send mail to the buyer and make sure they got the stuff anyway. They probably wouldn't lie about foraged material... it just isn't worth enough to lie about!
In the meantime, you probably should bug report it if you haven't already. You don't want SOE to close your account while they try to sort out the details and determine that it was an honest mistake.