you didn't hit something. you either tailblocked it or landed heavy on the tail and snapped it.
it is physically impossible for that damage to happen 'just riding along'. it isn't a defect - its damage caused by the way you rode it.
^This, if you hit a big rock the base would likely be tore up. I've done the same thing, it happens, hitting a windlip, ollies. btw what's your weight and the weight range for the board.