I think the empircal element is there in people offering to demonstrate it very openly. Several people have met Dan, Mike and Rob/Akuzawa now and have reported impressive experiences. Dan is reported to be able to stand in an ordinary stance and not only not be pushed over, but make the one pushing him become weak and unable to lift his feet--or make him fall. And he is said to be able to generate tremendous penetrating impact with almost no motion. Likewise for Mike Sigman, according to no less than George Ledyard. And you can see videos of Akuzawa doing some pretty eerie stuff.
So, does this mean Mike still needs to "go somewhere quiet"? Amazing what a difference a few days makes.