I think you've hit the nail on the head Jorgen:
I was asking a senior instructor what you do if someone jumps out of your hand or reacts in a completely bizzare way to your technique (such as running at you stupidly, dropping to the floor without you doing anything or letting go and just standing there). He told me that I have to respond to what uke is doing NOW not what uke should be doing.
This same instructor used to talk about living in the present and not the past or the future - I used to think it was some hippy zen bullsh*t, but now I realise what he meant.
Just going through the motions of aikido techniques is OK for beginners, but at the end of the day we have to get to the stage where we can react to what a person is actually doing - and therefore every throw is different 'cos we are not 'doing a technque' on someone - we are blending with them such that a technique appears.