Again I seriously doubt it was fuel dumping.
You know many hours in advance if you're going to land overweight from excess fuel, and in the 747 all you do to fix that is bump the speed up. I've spent about five hours at M 0.87 to burn off the excess because the Captain was a tad overcautious when ordering some before departure.
And even if you do arrive with a bit too much fuel all you do is get the flaps and gear out early to burn off some more.
It's not rocket science!