At the risk of expressing the fact that I am no doubt out of your guy’s league when it comes to the technicals of aviation. I did a quick search and found no less than 3 cases of Boeing 777’s dumping fuel. And also a couple videos that claim as much.
http://www.liveleak.com/view?i=69b_1285076425
http://www.youtube.com/watch?v=RlaUOEa2UGY
Reread my post. I said “most.”