Well, let's take a close look at what he said, and what he did.
1. He said that it takes less effort to drop your elbow. Think about that for a minute....which takes more muscle and energy, to not drop your elbow, or to use more muscles and drop the elbow?
2. Now, let's look at something else he said. He stated truthfully, that if you drop your elbow before you make contact, you will have a tendency to hit the cb too high.
3. So, let's now look at what he actually did. He barely dropped his elbow before contact, which is normal for a pendulum stroke...no drop, or a slight drop.
So now, we have to ask ourselves a few questions....
1. How long is the tip on the cb? (.001 sec., or about 1/8 inch)
2. Since the cb is gone after 1/8 inch, what point does an extended followthrough have?
3. Since he isn't hitting the cb with a dropped elbow, just dropping it for the follow through, and the cb is already long gone, what is the point of dropping it supposed to add? It can't be less effort, it can't be smoother if you need to add more muscle to do it, so what exactly is the point of dropping it?