Ni-dan here, Mu Duk Kwan. We had white belt kids breaking boards. I mean children. This is just...embarrassing. It's pure speculation because I wasn't there, but I noticed no concentration, no voice, no dynamics, just going through the motion. The problem is that even just going through the motion should have been good enough. It's a board, f'Petessake. A black belt should be able to break through that much concrete because I had to and I'm a wuss. Embarrassing.
I uploaded my black belt test from 1987
go to the very end, I tried to break 4 2” concrete slabs
only got three
http://www.youtube.com/watch?v=hdyeSNb2gtQ