gvwr?

I have a dump truck. Has 12k front axle, 19k tandemns in rear with 11r 24.5 rubber. Front tires are load range H and rears are load range G. My question is that i got pulled over for DOT inspection by a Highway patrol. I was running empty at the time but the officer told me that i had registered my truck for too much. Its registered for 50k but he said i could only haul 47k. Does anyone know how he came about that conclusion? I wanted to ask him but he was being a total ##*H**E...lol. please help becouse i will make less if i only haul 47k. the tag on my door say gvwr 50k so i am lost. please help by the way i am in texas