Here's my thoughts on that concept:

The idea of a "finished" gunfighter is the point where a gunfighter reaches his training plateau. He is no longer increasing his skill set in leaps and bounds as earlier in his career, but making slight changes to increase his efficiency. He is not learning fundamentals, or even practicing fundamentals rather making adjustments to his life to make the fundamentals a more fluid and natural process. Studies change from how to do something to why someone else approaches the same task. Training becomes not to increase speed or accuracy or even to be more consistent, rather to maintain what he has spent years building. Speed and accuracy may increase as a by product, however the difference is often not very noticeable and can be attributed to in increase in efficiency, not technique. I think this can apply to competitors as well, however the desired end result is different than a gunfighter.