I checked with another contact and they said that because they all still wear the black&white belt for closed-doors training with the regional manager, some people try to show some sort of dominance over the 'lower' belts.
This is particularly true in situations of brown belts sparring with lower coloured belts. In GKR, brown belts are allowed to use foot-sweeping techniques, but lower belts are not permitted. The higher belt is supposed to spar to the level of technique the lower belt has attained, but using a 'higher-level' technique such as a foot-sweep (which is laughable in itself) is used as a demonstration of rank.
An example of this is one particular brown belt will use sweeps as a get-out-of-jail card when sparring lower belts. He'll use the technique that the lower belts aren't permitted to use, and then apologise, claiming to have forgotten what colour belt his opponent really is.