On Chicago's last possession they botched a snap and Phili recovered it but they gave it to Chicago 1st and 15. I hadn't been playing complete attention so I didn't see all of it, and I thought I heard the announcers explain that the ball never left the ground and that there is a rule that protects against that due to "bad fields" (and the gave an example of the old county stadium that we used to play in). So do I understand that correctly, if you don't get the ball off the ground on the snap is it not a fumble, just a penalty or did I miss something?