The chair broke because Dominic was sitting in it improperly. But instead of telling someone, he just propped it back up and balanced it on the broken legs. That way, when the next person sits on it, it will look like they broke it.
"I don't want to get in trouble and have to pay for a new chair," Dominic shouted.
I wonder if it ever occured to Dominic that the next person to sit on the chair might get hurt. :(