If you watch the extras on the DVD, I think it's in the light and magic bit, you can see an unfinnished scene involving Chattar Lal in the cage being lowered into the lava pit.
And by the way, I'm a she, not a he.
I always thought that he was so busy talking to, and testing, Chatter Lal that he didn't even notice what was going on at the rest of the table until the monkey head was put in front of him.