Good answer. I am not sure I completely understand how to apply Mike Austins move though.
In regards to the guys who explain the kinetic chain. Lets take TPI for instance. You are correct in that it is the flexibility, mobility, stability, and strength in the various segments of the body that allow this snapping to take place. Not an effort of the golfer to do so manually. Some are more gifted physically and some have been trained to just do it better and faster.
The more powerful hitters segments decelerate faster. Again not manually, they just do it. Because they are physically able.
Now you can train your body to be more flexible, mobile, stable, and how to decelerate faster in the gym. Then as a result it will show that you snap it better. But just actually trying to do it probably won't do any good. Better for the golfer to just try to maintain his lag and drag and let that stuff take care of itself.
I wonder if “snapping the kinetic chain” is the cause of Tigers left knee problems.