You are the tard, not him. Look at mervins description for btx. Rocker in the middle and flat/slightly cambered zones under foot.
1st they have always been the same flat-mild camber under foot. Even if they didn't advertise it. 2nd there is such this as tolerence in quality control.
And you don't think there's 'one offs' of anything? I saw a gnu board for sale with a different base than the model was supposed to have.