If someone mistaken it as trash and throw it away when cleaning up the gallery, then it is not art.
If trashmen are arguing whether or not a piece is art, then it is borderline art.
If they ignore it, then the art piece is art.
Otherwise, we have no standard at all, and the art world would only belong to elitist who can't draw a damn and status seeking idiot who up the price of a particular 'art piece'.
Beautiful is not in the eyes of the beholder.