SLE isn't all about the strength of your application, it is more about recruiting. They want to see kids from under-represented areas come so they'll tell their friends back home how great WP is and so on. If you aren't accepted and you are a great candidate don't worry about it because it does not mean you won't get accepted to the academy. If you are accepted try to have fun and learn a few things at SLE, that's what it's all about.