Just a little theory exercise: Your G is nothing more than L/w, which means that by decreasing w, we're also increasing G if the rest stays the same. I don't know how much weight is in a full hopper (relative to total weight of the aircraft) but dumping half your weight would effectively put 2G on the airframe. If you also initiate a pull-up, you need to add that to the Gs already there from the dump. This is based on everything else staying the same though... so keep in mind that the aircraft rising, airflow changing etc will have an influence too.