You just witnessed Scott Pilgrim being "defeated" by Matthew Patel. It's been...curious to see. Anyway, you don't quite understand what's happening. Once Ramona leaves the place, ignoring Matthew, everyone does the same. Little by little everyone leaves the place while Matthew complains, demanding recognition for winning...Until it's just you and him in the concert hall.

"...Damn it!"

He complains, stomping on the ground and then crossing his arms.