Thanks all for your responses, we do a lot of bunkai and application work with kata and agree that they are a 'practical textbook' of sorts but we could not understand why, when the rest of the kata is done quickly, these moves were done slowly and quite precisely (changing of angles, looking in the opposite direction etc). I like the theory that it could be either done in the dark, a slow arm lock etc and it could also be to show the technique and practice it slowly to perfect the action. I am training with my senior sensei on Thursday and will discuss and come back to the thread. Thanks again.