It looks like Dottie may have forfeited the game for her sister. But it could've been Kit legitally making the landslide without assistance
Could have gone either way but if I had to guess, I'd say Dottie intentionally dropped the ball. She was just too good to fumble something that big and it was clear she never cared that much about the game anyway. She also knew Kit wanted it more so she decided to let her have the glory at the end.
Yeah Dottie only did it for her sister and after the revelation that she was always perfect I think that made her throw the game. It was that or her sister. The choice was easy.