Originally Posted by Tight Lines
Look at the one forehand hit at 0:28 when he is being pulled wide. He is doing the drop step/gravity turn.
I agree. There he is using a variation of moving the rt foot first. Seems he sort of steps out with the right to get his wt in that direction, but then the rt foot doesn't quite hit the ground till it's lost ground and actually seems to touch closer to the left foot it had moved or started. Maybe that is what is called as a drop step.