interesting... watch the instructor's demonstration at 0:32 and the student's after ... note the differences.
The instructor's crown stays pulling upward and his head doesn't really drop in space, meanwhile his legs bow, kuas rotate and his spine does a closing bow to create opposing forces that result in the dropping power. The student is trying to replicate the same by dropping his whole frame and head.
Unfortunately the instructor's only feedback for correction is "too much tension" ... not really helpful. Of course tension will prevent the student from using all the right components properly but he's not being told what they are..
I like the pelvis throwing drills in the first video.