Did other people announce it every time they put a tray in the back ? No , they didn ' t . As you hadn ' t assumed any special responsibility for the tray or was aware that it was somehow extra special , you did what everyone did with every other tray . It was up to him to keep an eye out for the tray or to inform everyone elses that special care had to be taken with this tray . He knew were the trays were being put and it was up to him to keep an eye out for when it was put there and take care of it . You did what you were supposed to , which is to put all the trays in the back when done with them without making a public announcement . It ' s not on you that the other kid didn ' t keep track of his tray or normal tray procedure . You ' re not a mindreader .