Think you are all missing the original point of the post. This guy has "not" failed pilot aptitude, he failed observer. As the RAF doesn't have observers I don't see why this matters. Go to OASC and give it a go with the scores you already have mate.
And don't give up til you have a piece of paper in front of you from a very important person saying "sorry bloke but we're never going to let you in"
And then try again. If its what you want dont give up.
I-C