Damage from a hard landing is not usually readily apparent visually. That's why there is a mandatory hard landing inspection after such an event. However, the label of "hard landing" is subjectively applied by the PIC and therefore subject to his own integrity.
An airplane as advanced as the A380 may also have electronic measurement of g-force and sink at touchdown that may drive a hard landing inspection.
As far as a relatively light GW airplane always resulting in a firm landing by one poster, here - baloney. Of course, my experience in jumbos is limited to 747s and I don't have any A380 experience. Lighter weight 74's are a little more difficult to finese, but not scary like that landing. Landing in a crab like was done on that A380 landing is very hard on the landing gear. I'd be interested to hear what the flight manual has to say about landing in a crab.
Sorry gentlemen, but that was a BAD landing. We've all done them.