" "The scrutineers found hidden in the wing a leaf spring attached to the end plate and covered in a rubber housing that was painted the same colour as the wing to disguise it. The spring was designed to flex after a certain load had been passed, conferring an aerodynamic advantage. This is why Red Bull were excluded - the infringement was considered much more serious than simply some overly flexible carbon-fibre - about which it can never be certain it was not simply a team going a bit too far by accident - because of its obvious deliberate nature." ""
Devious stuff. Was always the case in motorsport, at all levels.