The display manoeuvres were calculated to be in the region of 3G and well within the capabilities of the aircraft. The non functioning G meter should have read up to 9G, so while damage might occur below this figure, the manufacturers clearly thought that the airframe would survive this amount of force and be capable of landing safely for repairs. I seriously doubt that any pilot would want to pull more than around 5G in what is essentially fun flying for the purposes of entertainment.