Any bus or truck that I have ever filled that has dual fillers has barfed various amounts of liquid gold on the ground, in varying amounts. A guy could make up a whole bunch of reasons why, and some may or may not be true.
Tom, as usual, is dead-non right that the best fix is to use the civilian diesel pump and avoid the dreaded barf all together.
For the drama queens, you can fill both sides at once and try that. Probably would result in two pools of diesel instead of one.
Finding a 'quiet space' at a Flying J is something I have yet to achieve in life.