I think people are making very valid points about this being a test and more a test of spirit and heart than anything else. But I would still argue and maintain that this type of sparring and experience does teach something. At the end of the day it is pressure testing. Look at how crisp and perfect his techniques are when he is doing his katas and bunkai. Then look at what happens when he meets a fully resistant opponent. There is a hell of a lot of grabbing and tusselling. The instructors need to see how the student adapts his technique and training to a little bit of chaos. The guy did so well, there was no showboating or posturing he just got down to business and you could see the level of the mans skill when he managed to fly out a kick from nowhere whilst under pressure and the dynamics of his punches when he was using the non punching arm to pull the opponent on to his punch. I imagine that the man is able to do this because he has been taught how to do this. This type of full on traditional sparring teaches people how to use their techniques under pressure.
In your post you use the example of car manufacturing
Well I would argue that a great deal of pressure testing goes into making cars safer. Have you seen the crash test dummies been driven at full speed into a wall? It is a way of pressure testing the car's impact bars, seatbelts, airbag etc. I would not want to get into a car that the manufacturers had not used pressure testing at some stage in the design phase.
Absolutely spot on!! many people have the idea their perfectly honed techniques are going to work on the street and their fight will look as pristine as a Jet Li film fight, it doesn't work that way though. Fights look untidy. People tussle and brawl even the best MA will, the trick as this guy showed is to be able to pull off your techniques regardless.