Niles walks from the kitchen carrying one plate of fruit-and reappears the other side of the door carrying a different one.
Niles alibi was that he was traveling in Africa; one of his guests asks him about his travels "on the sub-continent". India is the only sub-continent; Africa is a continent.
Niles, with his attention to hygiene, would not keep a bird in the kitchen.
It's inconceivable that the group would continue playing their "game" after someone had passed away. Martin, especially, would have called a halt to the proceedings and initiated the proper legal proceedings to handle the situation.