Answer to The Case of the School Grudge Match

Wong entered Ms. Xie's C Team in the match against the opponents' A Team. Ms. Xie's girls lost that match by a wide margin. But that left Ms. Xie's A Team to play against the opponent's B Team and Ms. Xie's B Team to play against the opponents' C Team, putting the odds in their favour in both matches. So the Factory Road Middle School won two out of three matches and was declared overall champion.