Why was Willie so stunned at the end of Chapter 8?

Willie was stunned that Mr. Tom stood up for himself..... that he confronted Mr. Ruddles.

"The front door wuz open, Mr. Oakley, and I saw a definite chink of light from where I wuz situated."
"Oh, and where would that be, Mr. Ruddles?" asked Tom, a little perturbed at so many dramatic entrances in one evening. "Would that be from lying on the hall floor with yer nose under the door?"
The twins at this point turned hurriedly away and bit their lips. Charlie stood back aghast. "I won't go into the legalities, Mr. Oakley. There were a definite chink. Don't you know there's a war on!" And with that he slammed the door and everyone except for Willie, who was feeling somewhat stunned, erupted into gales of laughter.