I think this shot is produced by swinging in a way that the lag is released late causing the low shot to be made.
But this is not by holding with the wrists....
I've noticed that when Mcilroy and tiger play this shot, that they seem to release across the ball... and a half follow through occurs
I've been feeling this on the practice range with some good results.... Anyone else play around with this shot? Maybe someone can shed some light on this so we can further understand what is happening.
It feels almost like a slight dip or delay from the top of the swing.
Here is a video which shows what I mean, look how the lag is seemingly released across the ball